Singles died this year? Singles actually made a comeback in 2005-06! Vinyl overall was the only improved sector, growing by some daft margin considering it's 'death' in the early 90's, in the music software area last year!
The Vinyl market is now healthier than it's been for over a decade. It's not just for 'dance' material either. There has been renewed interest in the mainstream as well, with heavy duty 180 & 200 gram, re-mastered vinyl re-issues gaining a good following and sparking renewed interest in general. We are finding more and more people adding a turntable to their existing kit, either for the first time, or for the first time in some while. New marques like Project and Avid have made strong inroads into the marketplace at the budget and high end respectively.
However, before you shout 'hallelujah', as Jumblemo says, this is due to a strong, and growing stronger, niche market -
not mass acceptance. The masses are in fact switching to downloads, a fairly modest form of Digital replay (yes, even with 320 MP3's) and as such the musical market appears to be polarising. At one end, the audio enthusiast is getting into Vinyl, hi-res, and quality CD's, at the other, downloading and mass digital storage. The divide is along the lines of those who want convenience or high quality. Both sides have a case.
As such, I would filter out your vinyl. Ebay is a good starting point to check on prices, as are the local record shops. You tend to find stuff that sold by the lorryload, but are musically a switch off now, Status Quo etc, you can't even give away. But stuff like the Nirvana singles go for a bomb! Mobile Fidelity albums are a quick path to riches, original pressings another. Vertigo (swirl label) originals fetch silly prices, as do Island originals. Cult artists like Nick Drake are another source of good income. The retailers are offering his albums for anything up to £400.
Get hold of Record Collector, check ebay and see what's selling. Albums and artists tend to go in phases. King Crimsons 'Court of the Crimson King' for example is popular at present and is going for upwards of £35 depending on condition. Mike Oldfield by contrast is deader than Afghans!
It's a good market, as interest, believe it or not, is high at the moment.
I would agree with Jumblemo, that it might be an idea to keep them, but only if they are going to get played. Or, alternately, if you have a TT still, transfer them to digital,
then sell them off. This is another option that those who cannot either afford, (or want to) replace their vinyl with digital media.