Then don't let sdice transactions into your solved blocks, and encourage others to do the same. Mike didn't say you have to increase the soft limit. Luke-Jr posted about your other options.
Personally, banning sdice outright seems like the kind of scummy meddling bitcoin is supposed to solve. I would rather make them pay transaction fees somewhat proportional to the cost they incur on the network. If they pay them, miners get more money for their trouble, if not, they stop spamming the chain.
It does seem like the decent thing to do, for our casino we simply pay the network requested fees on all out payouts and adjust our margins and payouts to compensate. We even modified our dice game to make losing payouts an option for the players.
We like satoshidice (we kind of have to, we modelled some of our games after them) but we would like to see them take a more active involvement in resolving this issue that affects us all.