There's very little seriously rigorous blog research in my humble opinion. Susan Herring's brog, (we)blog research on genre, project was all over HICSS with good stuff. I have quibbles with some of their methodology, but at least it's clearly documented, the conclusions are argued from the data at hand and I could try to reproduce the results if I wanted to. Besides they have whizzy pictures!!
P.S. Tom Erickson and Susan Herring throw a pretty good mini-track at HICSS. I learned a lot and had a number of great interactions with folks like Jon Seely Brown, Dan Russell, and Jim Holland. Enough name dropping, eh!. If you can pony up the cash and time it's well worth the trip, independent of the location.