There seems to be one early trend emerging in the wake of moving kickoffs to the 30 yard line:
So far in 2007, a significantly higher percentage of kickoffs into the end zone are being returned rather than downed. So, not only are fewer kickoffs landing in the end zone this season, but more of the kickoffs that do land in the end zone are being returned. This tells me that teams have decided to be more aggressive in the return game because of the five extra yards of space provided by the new rule.
The trend looks to have accelerated, in that teams were more aggressive returning kicks into the end zone in the second week of the season than they were in the first (experience factor, maybe?). Interestingly, none of this is translating into more returns for touchdowns.