It is not the government that is consulting local people on which they would prefer; libraries or adult social care. This is a consultation that has been setup by Lewisham Council prior to the comprehensive spending review. Everybody expects that cuts will be necessary to all areas of public services (and all parties made this clear prior to the general election) so Lewisham is right to be carefully considering where the cuts need to be made. Whilst we may all hate this process it is better than the problems Greece is going through.
On the issue of libraries, I don't want to see any libraries close, but it is worth remembering that Britain has one of the highest rates of public libraries anywhere in the world. When looking at library books per capita, the UK ranks above every major industrial nation (other than Russia) and has twice the rate of France, Italy, Netherlands, and Ireland. That doesn't mean that it is right to close libraries, but I think it answers those who complain that there are not enough books in libraries.
Although we are not quite there yet, I can imagine a time when all books are available for free on your Kindle/ipad, paid for by small adverts or an advert free subscription - just like Spotify (big business opportunity for somebody to develop this if Amazon/Google haven't already). At that time we should recognise libraries primarily as community education centres not as places to store books.