Personally, I can live without the Ki power source. I totally agree with their decision and reasoning on that point. It might as well be Power Source: Asia. Most of that can be covered by other power sources just fine.
As for the mechanics, that's a good question. I would like to see another full discipline class, or an expansion of that model into other classes (I suspect with the Thief, we did). I wasn't as keen on Augments, but that could have been because I don't like the flavour of Psionics in D&D, so I may not have given them a fair shake. Refluffed, who knows... I might love the idea.