tedster - 6:29 am on May 10, 2011 (gmt 0)
When I first read your observation, I freaked just a little because there are a few internal pages where I struggled for a long time to get them to rank instead of the home page. Fortunately for those sites, those internal pages I worked so hard on are still ranking for their longer tail phrases and I'm not seeing any effect like you mentioned.
Maybe someone else has noticed it in their niche, however. It is the kind of thing that has tended to see-saw quite a bit.