Lame....I've been reading similar things on the diablo forums about how handicapped barbs are in inferno. I've got the health and dps but my resists aren't high enough. I also haven't been using the enchantress so I guess I'll have to use her to get whatever buff you're talking about.
Yeh, she is absolutely vital because she provides a 15% armor buff (!). As well, her mind control is pretty useful because it works on bosses and elites.
I still really enjoy the Barb playstyle, although I wish I could build more offensively and still succeed in Inferno. However, what I hate is that Barbs are yet again so insanely gear dependent. It's not that Barb's can't succeed in Inferno, because there are some who have killed Diablo with 5 stacks ... but those who have are generally wearing gear that has a collective value of 50-100 million gold. It's not that Barb's aren't viable, you just need to spend a lot more gold as melee than ranged do.
Ranged still suffer from problems because most of the times it's better to stack nothing but damage. My WD will likely have less than 20k HP because I'm aiming for 60k+ DPS ... the point is to use invuln CDs and burst things down before they touch you. Everything 1-shot kills ranged, even if they build defensively.
The problem for Barbs is that the most viable way to succeed is to stack damage reduction/mitigation items. You want to try and get close to 50% block, a 15%+ melee damage reduction String of Ears, Stormshield with 30%+ block, etc. However, many of these items don't have any All Resists, so you then need to spend millions to get 70+ All Resist in every slot that you can while ensuring that you have a good enough weapon to offset the massive DPS loss that comes with transitioning to this gear.
I've usually welcomed the challenge of playing the most gear dependent classes, but this time around I just don't care to have to farm that much gold for my first char to beat Inferno. I'm just going to dump 15-25m into a WD and then mad farm Act 3/4... if I ever want to restart my Barb, I can just feed him gold/gear with the WD in late Inferno. Otherwise, I'd be stuck in Act II until I gathered another 20mish gold.
This problem is made even worse in coop games past Act I. Ranged classes can work together and kite, which is basically how they'd play solo. Barbs go from being able to somewhat tank mobs (solo) to get 2-3 shot by elites in a coop game. You basically need to significantly outgear the content you're clearing in order to have any chance at coop.