If the Devs really think SD is a problem, they haven't seen anything yet. Bitcoin can't handle more than 1000 transactions a second? There is no way a Bitcoin will have value in 20 years!
Handling 1000 transactions per second for 10 active users (SatoshiDice) and handling 1000 tx/sec for 100000 active users are two
totally different things.
The latter grows the infrastructure, the former overloads it.
Filtering out satoshidice transactions would make it trivial to double spend a losing bet.
If it takes double-spending to stop SD's abuse, then it's good that it's easier to do.
If SD is going to take the "tough, we don't care about the problems we cause" road while they abuse the network, I don't see one reason why the network should give a care if
miners exercising their by-design choices makes SD more vulnerable
because they don't even follow common best practices in accepting transactions.
While I agree that
eventually the block size limit may need to be raised somehow, that day is far far in the future. With miners doing their job filtering out flooding attacks (the only major one currently being SatoshiDice), we are nowhere near even the soft limit being a concern.
Bitcoin's scaling problems are mostly limited to using the blockchain. There are many ways to avoid using the blockchain. Already, the vast majority of Bitcoin transactions (yes, even more than the SD flood!) occur within MtGox's system never touching the blockchain! The new payment protocol should help with some use cases as well. There are various possibilities for transparent trust-chain type transactions as well.
But all these different improvements require time to develop, understand, and implement in clients. With the current situation of active developers, it will probably take years before Bitcoin can scale nearly as well as competitors. Bitcoin Foundation is helping improve this situation by paying at least Gavin to work on things full time. Real adoption among rational people (ie, not gamblers or druggies) also brings with it an equivalent percentage of potential open source volunteer developers to join in the efforts.
SatoshiDice flooding the network does not. Anarchist nuts daring the government(s) to ban Bitcoin does not. These are counter-productive, and only harm the probability that Bitcoin will be able to achieve the adoption it needs to get to the point that it's truly viable.