Filtering out satoshidice transactions would make it trivial to double spend a losing bet.  Therefore I think it would be a bad idea for mining pool operators to make satoshidice transactions low priority or reject them alltogether.
If you make a bet on satoshidice, you will usually know if it lost before getting any confirmations.  If miners prioritized non-satoshidice transactions, then all you need to do to cancel your losing bet is double spend the coins with a high transaction fee.

More info is here: https://bitcointalk.org/index.php?topic=130764.0

Rejecting SD transactions is NOT a solution.