[G Larry]

The ideal scenario:
Nickles to Sen. Maj. Leader.
Lott stays in the Senate for now.
Miss. elects a Repub Gov. next election cycle.
Lott quits.
Miss. Rep. Gov. appoints a different Repub Senator.

[G.Mason]

'.......Miss. Rep. Gov. appoints a different Repub Senator."

Mississippi laws state an election for Senator will be held within 90 days of resignation, I beleive.