Have you been promoting your blog in any way? It may be where the traffic is coming from. One way I see where my visitors and traffic is coming from is by looking at the referrers, what people clicked to get to my blog. I believe if people have the URL to your blog, they can enter the URL without showing up as a referred visitor. Hope this helps.
Interesting. It’s not a new blog, as I expected it would be. I’m thinking that a search engine has finally properly indexed your site, probably Google. Google has been doing weird things with WP.com lately, certain blogs only. Pingbacks started showing up today as well. Something has been cleared out of the pipes, and I would expect your hits to remain high.