Personally, i love reactive abilities, but the problem with revenge in regards to a few tank equality issues that have been going around is this:
We can't use it while we are not tanking, and considering it is an incredibly cheap ability that accounts for a large portion of our total damage (given that we are actually being attacked and are able to avoid said attacks, more on that later), i would consider a huge penalty for when we are not actively tanking.
Some may rebut that the vengeance we get from vigilance (assuming of course that the other tank is still actively taking damage) will help offset this, although not fully since all tanks suffer from dealing less damage when not tanking (though arguably, even disregarding revenge, warriors are affected the most). Since i am not in beta, i can't know for sure, so this would be a question i would pose to a tank that is in beta.
The other thing with Revenge is that it's also not usable against mobs that spam a spell as their main attack, again i am not in beta, so i don't know how often this crops up or even if it does at all, but when it does happen on live, it sucks eggs.
So my suggestion to help solve some of the issues with revenge is to firstly allow Revenge to proc from direct damage magical attacks, and to replace the taunt refresh part (which will be sad to see go, but it must be admitted that it is quite an oddity) with the ability to allow your viliganced target to proc Revenge for you (either under the normal circumstances, or simply when he/she takes direct damage).