Whitey - 4:41 am on Jun 10, 2011 (gmt 0)
From what i can work out Matt says this is the "search quality" teams responsibility. I also get the feeling that the decision to pull the switch was a large commercial directive.
So in the context of this, a reason why sites won't come back is that Google want's to force more sites into advertising with them. Reversing this quickly will potentially be counter productive for them. So folks can carry on about search quality, but i think it has a huge connection with $$'s in Google's bank account and the ever increasing need to raise the share price.
Timing is everything in these updates. Search quality is simply a means to that end.