In my career as a warlock, I've been reached and hit many times. My survival largely due to the high ratio of defenders in our little gang. The shadow-walk concealment sounds great, but it's really just a patch for having A) little armor and B) giving Int and Dex secondary priority to Con and/or Cha.My experience with the warlock as a DM is that they are perhaps the most effective of current character classes. Very hard to kill (ranged attacks, concealment, lots of HP/surges if Con-build), lots of funky options, great flavor, and excellent damage output.
I'm not really bagging the class, just saying the W discrepancy needs some light shown on it. I don't think there's some major balancing compensation for the non-W classes that washes it all out. Maybe give those guys some feats that do for them what a Superior Weapon proficiency does for a {W] damage power.