Daily Kos provides some good reasons to challenge the results in Ohio. Not because the election is likely to be overturned, it's not, but because election reform has to start somewhere. And the problems in Ohio are extremely serious, and need to be addressed.
In the same vein, Washington State Republicans claim to have proof of voter fraud in King County. Good. If there was fraud, I hope they are able to prove it. Then we can have a new election and this ridiculous process can go to the point where everyone is so tired of it we'll be forced to reform. By the same token, if there was no fraud, I hope the Republicans get ripped to shreds by the public for trying to force a revote just because they don't like the outcome.