Just going off the statistics, my collection contains a third fewer books printed in 2009 than in either 2008 or 2007. There wasn't less fiction published - nor did I read any less - but my urge to collect and preserve was much lower this year.
What happened?
Speculating shamelessly, I think there are a few factors involved:
1) The writing cycle. We were lucky to get Morgan, Mieville and Abercrombie all at the start of the year. But then they were touring or writing, not to publish again until 2010 (I hope). KJ Parker and Scott Lynch were never scheduled to have anything in 2009, while Pat Rothfuss and George RR Martin are both in limbo. This isn't the complete modern fantasy A-list, but that's a good chunk of the people that are defining the genre right now.
2) Urban fantasy went through the roof. As much as I'm loathe to dismiss an entire sub-genre out of hand, I only see a few redeeming glimmers in the oh-so-darkness that is urban fantasy (Mike Carey's Felix Castor series, for example). Twilight-for-adults, supernatural-romances with lurid, covers of sweaty young women - nothing with permanence or lasting value for either the fantasy or the horror genres. In all fairness, I think steampunk is now in the same place, but with better cover art.
3) Young adult fantasy went crawling backwards. Thanks again, Twilight. 2007 gave us Un Lun Dun, 2008 gave us The Graveyard Book, 2009 gave us Mormotrash regressive fangst fiction. Harry Potter wasn't genius, but at least it brought semi-intelligent, entertaining young fantasy to the forefront. Twilight has promptly punted it back into the shadows.
4) Science fiction is still having a siesta. Although having Kim Stanley Robinson, Iain Banks and Neal Stephenson producing new work is never a bad thing, it still feels like we're in a holding pattern while the next generation of authors finish sorting themselves out. Fantasy is waxing right now, but that doesn't mean science fiction needs to wane... (more morbid post on this topic from Mark Charan Newton)
5) Fizzle. I was not blown away by the hyped summer and fall releases. (Many were reviewed on this site already, so I won't pick on them further...) Unrelatedly, some of the best 'new' books were simply international cross-selling (2009 was the year that Brandon Sanderson & James Barclay traded markets).
All the complaining aside, there were some definite bright spots, including some great books and some promising new series that will keep rewarding readers for years to come. Stay tuned for the glass-half-full.
