Nice article Fax. I hope to see others.

There's a very thin needle that needs to be threaded on class design. You want the class to have a niche, to be powerful within its niche, but to be flexible enough that you're not playing a machine that constantly does the same thing over and over again (the trap of many melee builds that focus on high charge damage, or tripping, or ranged attacks). This tension between niche, power, and flexibility is very difficult to do well.

Essentially, your gaming group just has to sit down and discuss what each person wants to do, and how they want to do it. This gives each person niche protection. Then you need to agree upon a general power level (always hard to balance in a party with casters and non-casters). And then you need to choose your magic items/feats/spells in such a way that you have more then one useful thing to do.

Discussions like this one help. Hopefully, 4th ed will help even more.