My new wallet went from 24 hours behind to 25 hours behind. I switched to the old wallet on my main computer, and that doesn't seem to be catching up either. I'm on public WiFi which is reported to be giving me a 30Kb connection. This has been fast enough in the past, but it looks as if it may be struggling at the moment.
If Bitcoin traffic is going to increase, then I may have to rethink my approach to running a node.
At 30Kbps, you should be able to download a block every 35 seconds or so.
On average a new block is created every 10 minutes, so if you are 25 hours behind then you are about 150 blocks behind. It should take you about an hour-and-a-half to download those 150 blocks at that speed.
If it is taking longer than that, then you are most likely connected to some peers that have slower connections or that aren't sending you any usable blocks. It's also possible that you are downloading the blocks fast enough, but that you don't have enough processing power on your computer to verify them very fast.