There was regression, as some older players did get worse, or stayed the same, even if their stats were pretty good. Manny dropped a point, a few others (off the top of my head).
I did see some injuries to pitchers, not a whole lot. However, that's really from at the All-Star break, since I just simmed to that point and then towards the end, so in the day to day and weekly operations I can't really comment on the injuries. It didn't seem too heavy or with too many injuries.
If I get time tomorrow, I'll try to sim through the second season, as the FA pool isn't quite as bad as I was expecting. I'll pay attention towards the regression more then, and try to stop once each month and look at injuries.