I have found the same thing that Alan has found--a relatively sewn-up market in the SF field primarily. After reading all the agent blogs, and speaking personally with my agent, it appears that the biggies are on the lookout for dark fantasy/paranormal/romance/erotica/thriller type stuff. In fact my agent asked me to "spice up" my urban fantasy and give it a more serious/dangerous edge.
We actually missed roughly half of the SF markets with my off-planet thriller from the likes of Prometheus, Del Rey, Ben Bella, Kensington, Spectra, Tor, Time Warner, Pocket Books, and a few others. They didn't even request the manuscript from the query or phone pitch. And of course, this was ONLY MY experience. But I found the trend disturbing. The market for SF is so narrow as it is, that once you get in there, you are still competing with the great midlisters and large guns of Benford, Bear, and the others. Tor, for example, are publishing the same people they did last year, with only a few exceptions.
Romance and paranormal thrillers are riding a high horse right now and laughing all the way to the bank. I don't know how long this trend is going to continue. Romance will likely dominate the market, as it always has. Our own Jackie Kessler (DragonJax) has recently sold one of these types to Kensington, and she has woven a great story around a facinating concept, if I may say so.
I'm absolutely brain dead knowing how the traditional/epic or road fantasies are doing out there. I don't write them. Perhaps someone can chime in about any market news concerning this genre.
Nowadays with SF you have to exceed/push the genre to the max to get a raised eyebrow. Concept or orginal premise is beginning to trump all there, in my opinion. Keep in mind, this is still a very subjective industry. Keep your eyes peeled on the Raylan's site for brand new imprints that are busting out of the larger, more established houses. If you find a new startup house for SF, for gawd's sakes, research them thoroughly and look them up in our Bewares thread to find out straight-away what you're dealing with.
I just sold an urban fantasy and a SF novel to a small publisher. We haven't signed the deal yet. We're fighting for rights at the moment. We might come out with our noses bleeding. So be CAREFULL.
Cheers,
Tri