While sites I haven't touched for 2 years that I couldn't give a crap about have been given a boost.
I have the same experience. I have a small site that has not been updated in years ranking in the top 20 spots where many of the other spots are national magazines or nonprofits. The magazine above my site in the serps for a reasonably competitive two word term has 9 million backlinks in Yahoo. My site has less than 30 backlinks for the whole site. Thirty backlinks versus 9 million, and those 9 million include many national magazines and other authority sites.
Clearly, at least in some cases, Google is looking at scoring metrics way different than what we are used to these past few years. So how is this site ranking for this key word? In past years this never would have happened, and now it has not only happened, but happened without any action on my part.