I'm not sure that Battlerage Vigor is that bad, it's the ability to use feats and magic items to improve on it that make it ridiculous.
Compare the class features of a level 1 Battlerage Vigor Dwarven Fighter with Con 18 with a level 1 Dwarven Cleric with Wis 18.
The Fighter gains 4 temporary hit points each time he is hit with melee or close. The Cleric heals that same Fighter 31 points per encounter with Healing Word.
So, the Fighter has to get hit 8 times for Battlerage Vigor to be more potent (hit point-wise) than Healing Word.
If the Fighter is being attacked by non-minions, the opposition only has to average 8 hit points per attack to knock him unconscious.
I don't hear anyone saying that Healing Word is broken.
Eh...yes and no. The difference here is that the Weapon Talent Fighter
needs to have a Cleric around to get that healing...a Battlerager doesn't. He can just do it all himself.
The real problem for me is magic items (if they exist) and feats that improve upon BRV. Improved Vigor adds 1 to 3, Dwarf Stoneblood adds +1/2 Con mod, and Bloodied Invigoration adds 2 when a Dragonborn is bloodied.
That's too much. At high level, the Dragonborn will get 12 per attack when bloodied and the Dwarf will get 15 per attack all of the time.
My house rule would be to not allow any feats or magic items to improve upon the base number of temporary hit points.
Granted, BRV is better than Fighter Weapon Talent. But, that does not bother me too much. If a PC takes a 16 Str 18 Con Dwarf BRV Fighter, that PC will have two defenses that are bad, etc. Good luck with having a not too balanced PC.
I was originally one of the people that didn't think that Battlerager was that powerful. That was because when it first came out a lot of people were creating these very imbalanced builds that were impractical. Things like a Dwarf with 14/20 STR/CON and every BRV feat there was. However, there's been a lot more balanced builds lately that can still hit just as hard, if not harder, than the Weapon Talent Fighter while still retaining their massive damage soaking potential.
The way I see it is that there are two problems here.
1) The feats that increase the effectiveness of BRV seem a bit overpowered. Bloodied Invigoration is okay, but Dwarven Stoneblood is basically a no-brainer and way overpowered. You can be gaining 6 THP at level 1, which is really strong. Perhaps the BRV healing should just be 1/2 CON mod in the first place? Then you'd only be gaining 2 THP per attack with an 18 CON at first level. Or maybe a limit where you couldn't have more BRV hitpoints than your level, or level + 1? This would keep it under control during the Heroic tier, while not tying your hands in Paragon and Epic.
2) The Weapon Talent ability is now pretty weak copared to the other builds. It needs something extra I think. With the Rangers at least, the Beastmaster build means that you don't get access to what is considered to be the best Paragon Path for Archers. With the Weapon Talent build though, there is no such incentive.
We may see the same sorts of issues with other classes in the new Power books. What are you going to remove from the Wizard, for example? Cantrips? I'm guessing it won't be Implement Mastery, although that would probably be the best for balancing the normal Wizard with a new build.
I think that maybe some of the core builds could use a slight buff. Giving the Weapon Talent Fighters a free Superior Weapon proficiency seems fair, don't you think? This way, you would have a +1 to hit and do a little bit of extra damage compared to a BRV or Tempest. They could catch up with a feat of course, but then your FWT Fighter is still a feat ahead. This would help to make the FWT more versatile and help to reinforce the idea that they're the "Weapon Masters" of the Fighter builds.