Darren Sumner argues that SciFi just wanted to get rid of the show in a long process of remaking themselves as a non-scifi network.
Also, check out the Save Stargate SG-1 campaign. Given that this cancelation is from the network only, and MGM and the producers want to keep SG-1 going, this has a real chance of succeeding.
My original post on the cancelation is here.
Update: This strikes me as junior high pettiness. Basically, it amounts to : "If we can't have it no one can. Well, we can have it, but we don't really want it. But that doesn't mean we want anyone else to be able to have it." They may be well within their legal rights to do this, but insisting on your legal rights is often inconsistent with basic moral decency, and this seems to be a pretty clear case of that.
I have to say that I really, really dislike the idea that people might have to have a good computer-based media system to watch the 11th season if they make it for download only. It would be pretty awful if the only way we'll be able to watch this is on a notebook computer screen with tiny speakers and no way to save them except on CDs that can't be watched except on a tiny screen. Even worse is that you'd have to pay for it beyond the exorbitant prices cable already costs. Ongoing stories would be nice, but if it's not on TV then they lose a huge audience that wouldbe able to watch them if they did TV movies or mini-series. Doing a whole season at its usual expense seems such a waste if it would be download-only.