You are assuming that we now have 48 votes to change the rules, which I doubt very much.
When Vice President Humphrey ruled from the chair in 1968 that the Senate rules on debate could be changed by a simple majority, he had 68 Democrats and 20 RINOs to work with.
He lost.
The number of Senators who will vote to reduce their own power is almost certainly south of 40.
Not to mention, the Miers nomination put every Republican Senator on notice that if conservatives can be this upset at the President - who doesn't face re-election - then they had better oppose this shameful abuse of power by the Democrats or else face defeat within the next few years. Quite a few RINOs, including the likes of McCain, Specter, Graham and DeWine have openly stated the Dems better not attempt a filibuster. For any other Republican Senator to support that filibuster now would be political suicide. Republican voters have finally had thier fill of Senators who won't stand up to the Democrats.
Republican Senators know if they let the Dems filibuster, they'll be looking for new jobs in the next three years.