Politico has an interesting piece on McCain's troubles with conservatives.
The piece notes that McCain suffers from fragmentation in the conservative movement.
The author points to the three strands of conservativism that will remain into the future:
1) Tom Tancredo's brand of jingoism and anti-immigrant ideology
2) Ron Paul's libertarian type that involves reduction of government, taxes, and many social controls
3) Mitt Romney's business-oriented brand, favoring corporativist development.
Good points, but not necessarily the real future of conservativism.
Out of all of those, the only one I find remotely favorable is the second kind.