Tiger plays a Scotty Cameron by Titleist prototype putter, Nike woods and irons. I believe his deal with Nike states that if he finds a better product from another company then he can use it.
As for the Nike putters being wooted right now, $50 seems to be the going rate for these things right now. Rock Bottom Golf has them on sale through Monday for $49.29 + shipping. Putters | Discount Golf Putters | Rock Bottom Golf