Update: An update to the followup. I got around to reading the actual postings on the site as opposed to just looking at the numbers. Silver doesn't hide that fact that he is heavily pro-Obama.
So on one hand, that means I'd be very wary of the numbers. On the other hand, at least he admits his biases so he's not trying to convince the world his site is something it is not. I apologize that I was confused at first. End Update.
In a previous post I gave a list of potentially good third-party sources of poll analysis and aggregation.
One of the sites I mentioned was www.fivethirtyeight.com. I noted my only concern is that it was relatively new and I didn't have a good feeling of any biases the site might inject into the analysis.
I've read a little bit more about it and there are some concerns that the site could potentially be biased. For example, one analysis credited Obama with turning Washington blue when that state has of course been blue for some time.
I haven't tracked down anything definitive yet, but I just wanted to amend my initial comments with this information. If you care enough about poll results to visit these third-party sites you also likely care if they are biased in some manner.