I wouldn't be too sure about that. If it becomes clear to republicans, that Clinton is likely to be the next president, they may just be able to negotiate with Obama to get a more acceptable nominee than wait for Clinton to make a nomination. You have a much more liberal court now with Scilia gone and there are some important cases going to be coming up over the next year.There is no way a replacement will be approved by the Senate in Obamas' term.
This should make the elections even more exciting.