@maxdancona,
I can't say what the Republicans will choose to do, but I think the wise strategy is to wait and see what the election results are before ramming a conservative nominee through.
If the Democrats are in a position after the election to retaliate by adding six seats to the Supreme Court and letting Mr. Biden pick all six new nominees, then the Republicans would be wise to not provoke such retaliation.
If the Democrats are not in a position after the election to retaliate in any significant way, then the Republicans should ram through a hard right nominee, and ram them through as brutally as possible.
The Republicans won't know which is the best path for them to take until they see the election results.
As for Romney, he seems a lot wiser than McCain. It looks like he understands that if he betrays the Republicans, the Democrats will betray him in turn.
McCain would just keep betraying the Republicans over and over and then get all confused when the Democrats didn't start loving him.