Oh yeah, I have been thinking exactly the same thing since the November 2008 election. Ubama thought that by appointing Hillary as Secretary of State he could "keep his enemy closer"? Heh heh, that's a two-way street.
Hillary will resign in 2010. She will make up some excuse, like “Bill’s health” or something. She will attempt to get the Democratic nomination in 2012, and lose. However, it will further expose candidate Obama and divide the democrats, and allow the republicans to easily unseat a sitting president.