Despite popular belief, conservatism (in the political sense) and 'change' are not mutually exclusive. Most conservatives are looking for a change, post-Bush.
It has been established that "change" can be either good or bad -- but it is important to also point out that change is philosophically neutral.
For example, picking Joe Lieberman as McCain's running mate would have given us "change," just as picking Sarah Palin gave us change. So change could have been a move to the Left or a move to the Right.
President Bush cut taxes -- but he also failed to veto spending bills. So electing a tax-hiker would be a form of change, but McCain can also bring about dramatic change by vetoing spending increases (now that's change I can believe in!).
Liberals assumed they "owned" change this year. They were wrong. Most conservatives want a change from Bush, and with McCain and Palin, they are getting it. What is more, Palin gives us philosophical change (she's more conservative), but also a historical change as she would be the first female vice president. As such, as a political cudgel, "change" has been taken off the table. Both candidates will give us change, so voters will now make their decisions based on some other criteria.
Note: This is a point I've been making for a while, but I don't think I've really spelled it out ... and I think it's important to make because it's at least part of the reason the Palin pick was so brilliant ...