Think it would be a good move. It would be another positive statement of intent from the club. With just any 'ol hiring I would get very nervous that Bale and Redknapp's chosen few would try to ditch, but I think the hiring of Ancelotti would give them pause to say "I think I'll give it another go..."
Great record / I think he'll be hungry for revenge against Chelsea / Spurs would be a great project for him. Not a complete turnaround, but a team that Ancelotti, I think, has the tools to fire into title contention. If Redknapp is a distinctly "English" manager, then I think Ancelotti would help in attracting big talent in the Serie and La Liga to round out the team, whereas I think Redknapp tends to be very xenophobic, except in the case of Croatians. Don't get me wrong, I think he's been great for the club. Redknapp isn't my favorite character, I wish he'd shut his fucking mouth. But, I think he was a smart choice in turning the club around. With Daniel Levy as a foil to his rather negative tendencies to sign over-priced talent, and also with Levy's pressure to strike a balance between experience v. youth/vigor, I think he's given Spurs what was lacking. Moving forward, though, I'm not sure he's the right person to launch the club into the next level. I think you can easily look at Redknapp and be a bit confused as to what he does really well. He's viewed as a great man manager, but then you look at half the team that he's frozen out and you have to wonder how he really is in that department... Also, he's viewed as a great transfer window man, but it looks increasingly like Levy is the main man pulling the strings during the window. To be fair, though, Friedel and Parker both wreak of Redknapp, and both have turned out to be excellent acquisitions that many fans were very resistant to. I think that Redknapp, rather than being a case of really propelling the team forward, is really just not holding them back.
Maybe Ancelotti isn't the answer. Isn't there a thread on here hyping Gus Poyet? Don't really see him getting the nod considering he left/was pushed out alongside Ramos just a couple of years ago.