If you were looking forward to getting gear upgrades through Honor at Level 70 when Wrath of the Lich King finally arrives in a few days, you probably shouldn't hold your breath. I know I advised doing a lot of PvP, but I meant that you should be keeping all that Honor for Level 80 rewards. Blizzard has stated that Season 3 rewards will not be available for Honor points, and that Brutal Gladiator items will retain their ratings requirement.
Zarhym explains that there are no plans to make Season 3 gear available through the Honor system because there will no longer be any new rewards for Arenas at Level 70. Since all Honor gear available through vendors are two seasons old, all current Level 70 rewards will remain as they are. In another post, Wryxian explained that the personal ratings requirements for Brutal Gladiator gear will also stay in place, pointing out that the gear will last well through the Northrend leveling experience. To that end, Blizzard intends for the gear to be "somewhat limited in availability."
What that really translates to is that Brutal Gladiator gear, and to a lesser degree Vengeful Gladiator items, will be sparsely distributed. In fact, the Season 3 and 4 gear you see now will likely be the last pieces distributed to players. Most players will be leveling to 80 and others who have yet to hit 70 will skip past the gear. Although ranked matches at Level 70 will continue to exist, the payoff will be so slow -- players will need to wait one week in order to get Arena points -- it makes no sense to farm Arenas for leveling gear. Since ranked matches will only be at Level 70 and 80, it means that players will need to stay at Level 70 for a long while just to get some gear that will eventually be replaced.
For all intents and purposes, Level 70 Arena is dead unless it becomes some strange new form of twink PvP. I highly doubt that because getting to Level 70 requires quite a bit more time investment than, say, Level 29 or 39. It is also the lowest level of the next Battlegrounds bracket, which means that players staying at 70 will be at a great disadvantage in any given Battleground. That's quite opposite the twink philosophy, which I believe should guarantee the death of Level 70 Arena play. There are also no end-of-season rewards for Level 70 at the end of Season 5, so players' best bets for PvP gear are Season 2 Merciless Gladiator items. Then again, S2 items should be easily replaced by Northrend quest greens and dungeon blues, so... you're probably better off saving your Honor for the endgame.
Arthas awaits and so do your questions. Find the answers you've been looking for that will help you with your journey into Northrend and to level 80 with Wrath 101.