It would be foolish at this point to put too much stock in the specific class changes and new abilities, knowing that Cataclysm has yet to enter the beta stage. Many of the abilities we've read will change in some form or even be scrapped entirely before the game ships, so we can't get too excited nor too upset with them. What they do give us, however, is an inkling into the developers' thought process and the direction they intend to take with the class. This, in turn, should help us envision how PvP will be like in the (hopefully) near future.

Death Knight

As Daniel mentioned in his analysis, most of the previewed abilities seem geared towards PvP. It's boring news for raiders, but awesome news for PvP-heads. Blizzard plans to introduce a new anti-healing mechanic with Necrotic Strike, something they backtracked on early in Wrath but seem to be giving it another shot. Working like a corrupted Power Word: Shield that eats up incoming heals on the death knight's opponent, Necrotic Strike is one more ability that defines Blizzard's vision for Cataclysm PvP: healing will be harder.

They also plan to give death knights another anti-caster ability called Dark Simulacrum, which replicates their opponent's next spell. Think of it as a preemptive Spellsteal or Spell Reflect. If it wasn't clear enough in Wrath, Cataclysm should firmly establish death knights as the anti-caster class. The anticipated loss of defensive abilities from frost and unholy should make those specs a little more vulnerable to physical or melee classes. Death knights had previously enjoyed a unique position of being able to handle most classes with relative ease owing to a combination of magical and physical damage, as well as excellent mitigation. If Blizzard stays its course through Cataclysm, mitigation abilities will be the domain of tanking specs.

If anything is indicative of what will define playing style in Cataclysm, it's the masteries. In the case of death knights, blood will be extremely resilient with the Healing Absorption mastery coupled with blood's self-heals; frost promises to have high burst potential with rapid Runic Power Generation; and unholy will be piling on Disease Damage, in a DoT-oriented playstyle. We'll learn more as Cataclysm unravels, but death knights should brace themselves for a dip in their defensive capabilities.

Druid

The funny thing about the druid changes is that the removal of a persistent tree form might have generated the loudest uproar among the druid community. However, the one thing that jumps out among the new abilities is Stampeding Roar, which Allison mentions is more oriented towards PvP. Sure, it will probably help some players get out of the freaking fire faster, but you know where this ability will shine? In the Battlegrounds. It's almost certain that the developers envision entire teams stampeding their way out of the starting gates in a rush to get to Battleground objectives. If druids are awesome flag carriers in Warsong Gulch now, wait until they break out Stampeding Roar and get their friends to, well, stampede all over their opponents on the way to their own base.

Balance druids will also get a playstyle change coming from mastery rather than an actual change in class mechanics. The Eclipse mastery necessitates that balance druids alternate their nature and arcane magic spells to maintain perfect balance, which makes their spell rotations somewhat predictable. On the flip side, balance druids must continuously strike a balance -- pun unintended -- between keeping an alternating rotation or choosing the most appropriate spell for the situation. Additionally, Blizzard intends to give balance druids a fun little toy in Wild Mushrooms. If planting invisible, exploding mushrooms all over a Battleground isn't trippy fun, I don't know what is.

Cat feral druids, in turn, will be even more rogue-like than ever, with the promise of a reliable interrupt. According to Blizzard, a cat druid should be a real alternative to rogues in Arena compositions, which can only mean good things. It also means that casters should be even more wary.

Hunter

As mentioned, hunters are getting a resource overhaul, which should make gameplay slightly different. The change seems cosmetic for now, but at the very least, this makes hunters immune to mana attacks. Brian felt underwhelmed by the new abilities, but mostly because he was looking at it from a PvE perspective. By any reckoning, firing traps from long range is awesome in PvP and it will become far more difficult to avoid them. Hunter crowd control should improve immensely -- the usability of a Frost Trap increases tenfold when a hunter doesn't even have to be in the midst of the fracas to use it.

Camouflage should also provide some interesting possibilities. Its largely a PvP spell, and should allow a hunter to fire off an opener from long range without getting countered. Nothing about the masteries indicate a shift in playstyles, however, as beast masters remain pet-centric, marksmen continue to be weapon dependent, and survivalists get an extra boost from utility abilities such as traps. Nothing new there. What should be interesting, however, will be the changes to pet abilities. Will hyenas lose Tendon Rip in exchange for their new bleed capability? Pets providing passive buffs to parties is phenomenally boring for PvP. It would be great if Blizzard offered one passive PvE buff and a utilitarian PvP ability for each pet ... considering that PvP seems to be a clear focus in these previewed developments, that might not be out of the question.

Mage

As if mages don't already find great demand in Arena compositions (or at least are a staple in one of the most enduring ones), they also get Time Warp, an arcane version of Bloodlust/Heroism. With large scale or Battlegrounds PvP being a main focus in Cataclysm, a mage becomes even more essential to the group. Imagine casting Time Warp while battling against the boss in Alterac Valley or the Isle of Conquest. In a race to the finish, abilities like this will make a difference. The movement boost is just icing on the cake. Just ask Christian, who's excited about this ability the most.

If a renamed Bloodlust/Heroism doesn't get you excited, then how about Wall of Fog? Blizzard specifically mentioned its utility in the Battlegrounds, and the possibilities are just fun as heck. Mages can throw Wall of Fog to stop the pursuit of a flag carrier in Warsong Gulch, slow down ascent up the Strand of the Ancients, or make the Dun Baldar bridge even more impassable. Placed in strategic locations, a Wall of Fog helps teams achieve Battleground goals.

As far as playing style is concerned, it gets a little interesting. The arcane mastery of Mana Adept makes it such that an arcane mage becomes vulnerable on two fronts as attacking their mana pool ultimately neuters, or at least weakens, their attacks. Hopefully we'll see the return of potions and other PvP consumables in the Battlegrounds in Cataclysm. If you think fire mages are suicidal now, wait until they get the a Life Tap-like talent which not only encourages them to go down fighting in a glorious ball of flames, it forces them to do it while cheering them on with fiery pom-poms. Oh, and the Ignite mastery basically makes fire mages like warlocks. Finally, there's the unexciting Deathfrost mastery which, at the heart of it, only means that mages should cast something besides Frostbolt.