Rage spec for juggs has always been amazing. Rage juggs got a small buff in 1.4, but you have to realize, this is their only high dps pvp spec. Vengeance CAN do well, but it's very rare, and it will never match Rages numbers.
The real change was that Bioware "fixed" the rage spec for marauders. And really, it was a small tweak. Before 1.4 berserk gave you free 4 stack of shockwave (smash buff that makes it hit so hard) and 6 free or possibly rage building vicious slashes. The issue was that, while these slashes did good damage and were free or basically built a full rage bar for you, they did NOT build fury. You could only begin building fury after you had expended those 6 slashes. The change means that you can start working on your next 30 stack of fury and turn it into more rage + shockwave immediately after using berserk, or very very soon after. The end result is as follows:
1. 30 stack fury + berserk builds full rage bar + 4 stack shockwave, you smash.
2. Vicious slash spam builds 30 stack fury. Go to 1.
As an added bonus, if you start "dry" (no rage or fury, no frenzy), you have force choke and crush to build stacks. This coupled with a battering assault or 2 will get you to your 30 stack of fury, at which point you can start the above cycle.
Now, I've already gone over in a separate post why Carnage is much worse than Rage in PvP in 1.4 and why. You can read that post in the Marauder forums, it is entitled "Carnage is Dead". So put the two together: Carnage is no longer as viable as it once was due to bubble stuns, sorc buffs, and rage buffs, and the fact that rage plays so much more fluidly now, and you have a recipe for exactly what the developer was quoted as saying earlier in this thread: all those anni/carnage maras are now trying this new and improved rage, and people are getting their faces smashed by it.
Now having said that, I want to point out a few things. Before we start crying nerf about rage warriors, we need to consider other classes as well.
I think everyone agrees that bubble stuns need to have their resolve generation increased to be proportionate to the stun time. This buff coupled with the fact that resolve is more "smart" now and doesn't fill a bar for overlapping stuns more quickly makes this game a complete stunfest at the moment.
PT PTs can still keep up with or out dps rage warriors, and they are primarily single target, while rage warrior is aoe. They have by far the best burst in the game. I think people are affected more dramatically when they see a smash go down that takes 4-5 people down by 1/3 of their hp, versus seeing a single person taken out in 4-5 GCDs by a pyrotech. The fact remains that pyro PTs still do the sickest and most useful damage in warzones.
Always has been annoying as hell. In my opinion, buff their sustained dps (for better pve usability), nerf their stunlocking.
I also have seen several people mention the 10% buff to the armor penetration talent. Most people see this as a straight up 10% buff to damage, and that is far from the truth. Lets say your average player has 20-30% damage reduction from armor. We will say 30% for the high end. From my understanding, 10% more armor penetration means that you will reduce their armor damage reduction by 10%. So 10% of 30% is only 3%. This 10% armor pen increase is on average only a 3% buff to our damage, less on light armor targets. This primarily was to help us with tanks and heavy armor folks.
Finally, I'd like to also add that Vicious slash got nerfed significantly, in that it no longer hits 2 targets with berserk up, which was a big deal in the old 1.3 and previous rage specs. When it crits for 3k mainhand / 600 offhand, times two, that is a pretty big deal. Granted, I'd never trade our current rage spec for the old one - the new spec just plays so much more fluid. The best way that I can describe the old style of Rage is "clunky". It just felt very obtuse and difficult to use, not very rewarding. The new spec is the exact opposite, and from hearing what devs have said, I think that is what they were going for. I applaud the devs for making the most "unfun / high risk low reward" spec into one of the most fun specs. You also have to realize, the warriors putting up truly huge numbers have gone through hell to remod their gear. With the amount of comms I have spent to remod my gear to full power/surge and str/power, I could have at least 3 toons in full war hero gear. Think about that the next time me or another perfectly geared warrior smashes you for 6k - It took 3 toons worth of PvP grinding to get that warrior up to where he is competitive in PvP. Valor Rank 97, that's what it took to complete my set. And I have been PvPing since the days of "Battlemaster Bags". Oh boy were those fun.