Im sticking with Google purely because when I look through the logs for my sites Google is always checking for new updates, far more often than Bing or Yahoo. (The faster they index the net the more relevant my search results).
I also like the new Google Show options where you can select Images, Videos, News, Blogs, Updates, Books, Discussions. I dont think Microsoft can be trusted with my search data anymore than Google so that doesn't even factor into it.
I also just dont like the Bing homepage.
I think Bing is here to stay and wont fail in the same way Live or MSN did, its good that Microsoft is putting their dollar behind something because it will force Google to stay competitive.
I dont have anything against Bing, but Google works for me and if it aint broke dont fix it.