You obviously haven't been playing close attention, because this issue has been discussed several times in various threads here.
Frist recessed the session for several reasons. First, because McConnell was recovering from surgery, and at least one other seator had a wife undergoing surgery, Frist was not assured of having the majority needed to keep the Senate in session in the event the Dems moved to adjourn. Second, and most important, he wanted to use this week to do just what the Republicans have been doing - building opposition to a filibuster within the Hispanic community. That is why you saw the news conference yesterday by those Hispanic groups supporting Estrada. That is why ads opposing the filibuster have been appearing on Hispanic radio and TV stations, and in Spanish publications. That is why you saw GWB appear on Telemundo to talk about the nomination. They are trying hard to prevent the Democrats from establishing a precedent by forcing this to a full-blown filibuster. If this week allows the Republicans to peel away a few more vulnerable Dems, the whole thing will fall apart by the time they get back into session, and they can proceed with a vote. If not, then they can go into an all-out filibuster and win by wearing down the Dems.
This may not be the way you would like to see things done, but by all of the stories we are seeing, it looks like it may be working, and that is what matters.
There was some specific talk about some senators' being targeted for assasination. That's why Frist let them go. Let's wait to see what happens when they reconvene.