A Luttig nomination won't happen now. The "Gang Of 14" deal only applied to the first and only nomination to come out of the queue, which was John Roberts. The "Gang Of 14" deal did not render a filibuster motion irrelevant for all subsequent nominations following Roberts. Run JRB through the process again, filibustered. Run Luttig again, filibustered.
I think one of the significant criteria for this nomination was that it not be grounds for a battle on Constitutional principle. Neither GWB nor the GOP Senate have the heart to battle for Constitutional principle - not at this time. Maybe because they don't trust the gang of 14, i.e., don't really have a majority in the Senate. Maybe because there is reluctance to repair the dysfunction that cloture abuse represents.
Hopefully, a future opportunity will arise where Constitutional principle and cloture abuse can be addressed, but this nomination does not seem to fit that bill.
McCain, DeWine and Graham strongly intimated they would press for the nuclear option if Bush's Supreme Court pick was filibustered. This was BEFORE he nominated Roberts. With these three, he could even lose Specter and have enough votes.
Luttig could be filibustered. But it's better than this.