Dan's moved to Movable Type
He doesn't mention Movable Type in his post about the new weblog, but tell-tale signs in the HTML, filenames and navigation (see here, the "previous | Main | next" you usually see in MT archive templates) all point to a MT backend. The other clue was his OSCON post several months ago.
The <admin:generatorAgent rdf:resource="http://www.movabletype.org/?v=2.21" /> line in his RSS is also a pretty big clue.
Yeah -- that too. :)