I don't like default home page except blank homepage. However, if I have to, I will use Google as my default page.
I'm a Google homepage fan, too. In fact, while working I always have a separate window open to Google. That way I can just Alt+Tab and do a quick research Google search for instant info or map location. Then copy the info I need and toggle back to my work page, uninterrupted.
I haven't seen anyone with Facebook as their homepage as yet. I remember back in the days when I had mine on Altavista. It's now set to Google Aust.