The U.K. Times has a story on David Hockney's donation of a major painting to the Tate (reportedly -- at 40' x 15' -- the largest ever given to the museum). He calls on more artists to follow suit: "More artists should donate. They should think about it. You can’t quite trust collectors who say they’ll give to the Tate and often don’t."
I can think of one thing that would help the cause here in the U.S.