I could go on and on about the new features included in Revenge of the Gnomes, but I'm sure you've heard about most of them already (like the subterranean hovercraft group-mounts and blue-pill, red-pill potions for alchemy). Suffice it to say that the feature everyone is most excited about is that the level cap is once again being raised another 10 levels, to a grand total of 110.
Like everyone else, you're probably wondering how in the world (of Warcraft) are you going to level your new Goblin Tinker character all the way through those tedious levels of 1 to 100? Everyone wants to try out the new content, but no one wants to slave away through Stranglethorn Vale for the 48th time. To complicate things further, Blizzard still doesn't want to add any more 1-60 quests in the lower-level zones (not to mention any of the Outland, Northrend, Emerald Dream, or Great Sea Expansion zones)!
Fortunately, though, Blizzard's got what you need! Are you prepared for the "/level" command?