In my opinion, getting mods is a bit of a pain. Every time Minecraft updates, you have to crawl through the forums looking for updates for everything, and if you have a lot of mods this can get very tedious, especially when it comes to pre-releases and quick patches.
My (admittedly rather lazy) idea is to have a single database of mods, each with its own 'tag', direct URL and version #. Developers would go to this website and add their mod, then users could navigate to the same site, punch in the 'tag' found on the forum thread (e.g. modloadmp, tmi, ic2) hit a button and the download would commence.
Additionally, if the database found a mod had not been updated to the latest version of Minecraft, when it is requested a warning could appear telling the user the current supported version of the mod and asking if they wanted to download it anyway.
This is all basically from the top of my head, but could this happen? Is it possible? Or am I just being really lazy?