In fact, YCnews is perfect, except it doesn't take into account voting that's going on inside a post. That is, if there are good comments under a post from many people (the more the better) that post should get a higher rank. Well, hm, like this one :)
Also, we need some way to search only 'idea' posts. Perhaps if news.yc had tags that would suffice, but otherwise this may deserve a different namespace. Not something one reads everyday but more of a tool to submit or search for ideas.
It was trying to do a lot of what's being described here.
I also tried to do something similar back in the day, a kind of "human capital investment group."
What any "group" that gets together like this will inevitably find is, 99% of people, or more, will just want to put up ideas. The people who would actually implement them (like myself and other entreprehackers on here), already have way to many ideas of their own that they don't have enough time to pursue.