Although I'm a lurker (I may come out of my shell more, though), I could possibly write some articles on philosophy or mathematics (in a way connected to skepticism, of course). I recall having thought of some interesting arguments I haven't often seen elsewhere, though I don't recall them at the moment (sleep might help that).
I do recall 1 topic I would definitely want to write about (rather, I'd edit the paper I wrote for my philosophy writing class into something more suitable for a blog post), though it's more social justice than skeptical: an argument for keeping assisted suicide illegal (it was a good enough argument to convince me, at least).
Also, wanna say Storm's idea sounds very interesting, I'd love to read more on those topics.