Fringe is good, but like other JJ Abrams shows, it does drag out a bit. The standalone episodes get a bit boring after a while. X Files crossed with Lost only works so far.
Sanctuary has a 4th season confirmed, although, its gone back down to 13 episodes, considering season 3 atm will run for 20 its a bit odd. SyFy are also moving the rest of season 3 of sanctuary to mondays, which is like the 'death slot' for sci fi. Although i hear they are doing the same for warehouse 13 and eureka. It seems they want to shove the sci fi shows aside so that the wrestling and stuff gets the premium timeslots on a friday.
I'm looking forward to Falling Skies when it starts, and Terra Nova when it starts in the fall.
V is ok, but whether that gets a third season who knows, same with chuck.
There are plenty of sci fi shows airing/coming soon, unfrotunately they just aren't set in space.
I'm interested to see what Brad Wright does now that Stargate has ended, think it was mentioned on gateworld that he's got a few tv pilots/ideas, so i hope whatever he comes up with it's sci fi, which would be the likely thing.