two german articles with rumors:
first one: soderberg says that he could imagine doing ocean's 13...but only if he finds a way to do a movie/story that's even better than the first two.
second one: same as below but there's a hint that the story of ocean's thirteen will take place in Tokio.
one more german article:
Steven Soderbergh said that "the guys", especially brad pitt, were urging to do an Ocean's Thirteen.
according to MTV Weintraub is interested in making an Ocean's 13:
Vincent Cassel (toulour) says he has been offered to play a part in a possible Ocean's Thirteen: