I read in April's blog that an anonymous person has donated $1 million to the M-prize. From the press release:

The anonymous $1 million donor cited a growing understanding of the real possibility of curing aging in our lifetimes as his reason for making such a tremendous investment. He first learned about de Grey's work from the popular press, even though most journalists take the easy path of characterizing de Grey - a respected, widely published figure in the scientific community - as an odd eccentric. The donor followed the Fight Aging! blog and the online newsletter of The Longevity Meme, both advocates of de Grey's work and the Mprize in particular.