A News Corp spokesman says it is not putting together a competing bid for Yahoo--which makes sense, given that it can't afford Yahoo. Time Warner, AT&T, and Comcast, as expected, are not preparing bids. (And this is good news: A Yahoo combination with any of those companies would also be a disaster.)
TechCrunch says Yahoo-ex president and current Quadrangle partner Dan Rosensweig is hatching a nutty plan whereby Yahoo is broken in half, with the media assets sold to NBC Universal and everything else (search) merged with Facebook. Not clear what Rosensweig/Quadrangle's role in this transaction would be, but it's very hard to see how this plan A) makes sense, and B) will yield more than $45 billion to Yahoo shareholders. (We also believe a straight private-equity bid is unlikely to be successful).
Google's attempts to help others put together a competing bid will also likely fall flat for the same reason: Unless Google is willing to step up and buy Yahoo itself, which would further antagonize already anxious customers and regulators, it's hard to see how it can provide enough financial support to a third-party to make another deal happen. Turns out $45 billion is actually a lot of money.