Google has consistently been 44% of my referring sites. It's been rare for it to drop much below that, and just as rate for it to be much above that.
For the last several weeks it's usually been higher, going to 46, 47 or even 49%.
The odd thing is that my traffic has declined to 2007 levels, which I can only attribute to a combination of the nice weather and less spending/interest in my niche. I doubt that Bing, Yahoo and the others would drop as a percentage of referrals just because Google is making changes.