Carl Zimmer (at The Loom) and
Matthew Cobb (at Why Evolution is True) have nice short write-ups (with links) on
Ardipithecus ramidus, our 4.4 million year old cousin.
Update: John Hawks' weblog has the most detailed runthrough and independent analysis of the Ardipithecus papers I've seen (starting
here). If your interested in Ardi, this is the place to go.