I've been thinking about posting this for a while and Ed's post jogged my memory. I'm about to go out insane from dissecting stored procedures and needed a break, so here's info from the past 30 days for this blog.
First up, Google Analytics browser stats. As a percentage Firefox has been stable, IE has been decreasing, and Opera and Safari have been increasing.
Next, Feedburner subscription stats. This has fluctuated wildly. At one point over 80% was Bloglines (which I've never even seen), at another point Madicon (which I've also never seen) was over 50%. Netvibes has been above 60% for the past few months.