I don't think Rafa will let him go so late in the transfer window as he hasn't left himself enough time to bring in a replacement. If it had been a bit earlier on then I might have said go for it but if he does it now I would definately say that he has lost his marbles

It's not a matter of having a replacement, as we already have Benayoun, Riera, Kuyt, Babel, Gerrard and Elzhar for the attacking 3 positions, while Torres and Ngog could play alone upfront.
Rafa might want to hold on to Keane as he feels that he could still prove his worth. no matter what the press would say about the price paid for Tottenham, Keane was world class and it's clear to everyone that he has a problem in Liverpool. he can't even control a ball.