The '07 shares common problems with the other Gen 3 2.5i's. Mine has 77K miles on it now.
Head gaskets will seap oil. My '07 started seaping at 72k miles. Not enough to drip, but the heads and block have wet spots. Keeping an eye on it, may run forever like that. Or I may change them out when the timing belt is due.
Rear shocks are totally dead at 77K miles. The Gen 3 rear shocks were far too soft from the factory. Gen 2 ('00-'04) rear shocks from KYB are the fix.
Front lower control arm bushings are soft and tear early. Mine are just starting to tear. Not a problem unique to Subaru, had the same problem with my minivan. They use soft, mushy parts for a quiet ride. I would prefer something that lasts longer.
Front inner CV joint boots, seems to be a short life item on all Subarus. Mine are fine at 77K miles. My '99 went 154K miles before the first one split, maybe I'll get lucky again.
Wheel bearings might be a problem, might not be. I know they were a problem on '05 and maybe '06.