While it's true that Fox has given a number of sci-fi shows a chance (a half-season), many get the axe. It's really a shame that Sci-Fi channel isn't getting these shows, since it's the SciFi channel (ignoring that SciFi is NBC/Universal affiliated).
Well, it's Syfy now...
I don't think it's so simple that Syfy (via NBCU) can simply grab shows that were canceled. For one thing, for shows on another network like Fox, the network retains the rights to those shows. Those rights can be sold, but in practice that rarely happens. Another thing is that many sci-fi shows are expensive. The big networks can afford that, but a small timer like Syfy can't. A big (but IMO not the only) reason Farscape was canceled was how much it cost to make, versus how much it was bringing in advertising revenue.
One thing I would have loved to see Syfy do was grab rights to show older sci-fi shows out of general syndication. Except the problem with that is again cost versus revenue. Anything that is going to have a good ratio is snapped up by bigger networks (see Star Trek). Anything that has a poor ratio is going to lose the network money. So it doesn't work as neatly as one might think.
Of course, Syfy has plenty of old shows. They could replay some of their old shows (
GvE, I miss you so). Cost is non-zero (royalties, etc), but relatively low. However, revenue from them isn't that great either, hence cancellation.. Plus, suppose one of them takes off? Well, too bad, most of the sets are stuck and actors moved on, so it'd be difficult to leverage into something profitable.
Still, it's nice to dream that NBCU would throw it's clout around. Except, right now, they don't have much clout at all.
Still, it's nice to dream.