Of course, that ignores the fact that the electoral college vote (NOT the popular vote) decides the results.
In the long run, I think I'd take the worst of the D/R candidates over a string of 8 consecutive elections if the consequence is ending the two party stranglehold.
The way the system works, without proportional representation, you probably will ultimately end up with two parties, but I'd rather replace both current parties with new competent-but-ideologically-distinct parties (like, say, a Green/Socialist/Union/Interventionist/etc. party vs. a Libertarian/Free-Market/Business/Isolationist party).
Parties also can implode and die (Whigs, Federalists, ...)
If you're reading this and live in California, you should strongly consider the 3rd parties on the ballot. Obama's got the state locked up by 15-20 points, so there's no risk in third party voting. Obama will win, Romney will lose. This will happen however you vote.
So take a look at the 3rd parties, and if one of them more closely matches your views, support them. Don't waste your vote on parties you don't believe in.
NV is a battleground state with a fairly small population, so even 500 votes with a common agenda would get national candidate attention in the 2016 race. That's probably the most effective way to influence Presidential politics. It does require a year or two to plan ahead, but NV is not a horrible place for some kinds of business, either.
I for one look forward to our new shoe-retailing overlords.