I'd like to see an additional tag - the time control the game was played at (this request is even more relevant for Blitz games). I'm sure this enhancement would be fairly simple to implement.
The second request may be more difficult. Would it be possible to store the ratings of the players at the time the game started or finished? If I get a PGN for an old game, the system currently will list the ratings of the players as of right now, rather than when the game was played.