Our very dear and hardworking Guest Agent, Jennifer Laughran answered a similar question to this in her thread (stickied at the top of this forum).
The questions was: does it make sense to hold off on querying agents about my .... novel until the economy, and hopefully the publishing industry, recovers a little? If publishing houses are pulling back on acquisitions, I assume agencies doing the same?
And Jennifer's answer was: As far as the economy goes, it is business as usual for us, and honestly, for most publishers. We still have to take on new projects so that there will be books in the future, and publishers still have to buy them. Of course, everyone is cautious and being very picky about what they take on - but that is nothing new.
Plus there was also a few questions about subbing in the holiday season.
One question was: should I sit tight until January-ish, after the holiday season is over? Or, should I go ahead and start sending out more queries?
And Jennifer's answer was (I shortened it a bit): Oh goodness me. PLEASE start sending out other queries!
Another question was: I have a quick question for you about queries for December -- do they slow down for you now? Do most agents go silent for the holidays? I'm just starting to query and I'm wondering with the holidays and all the terrible publishing news out there, if it would be better to wait until January.
And Jennifer's answer was: I am pretty much not sending any more projects out myself until January (except things that are already in the pipeline) -- but I spend most of December clearing off my desk, getting rid of old things, catching up on reading, etc. In other words, I am still working. I think that most agents are this way - we may not be actively SELLING, but we are still working. Somewhere in there - probably the weeks between Dec 18 or so and Jan 3 or so - lots of agents will take vacation. But so what, you can still query, they'll just respond upon their return.