Whiel a zip / rar of all the patches would be an effecient method for bulk download, to me it doesn't really address the fundamental issue. Out of a couple thousand patches, there are only a relative few that I would be interested in as we each have different musical directions.
I don't know if something like this would violate some sort of terms of service with Line 6, but to me a third party website with patches, done a bit better, could be very useful.
Regarding Stumblinman's "too many variables" observation, yes, you're right. It's not possible to do with 100% accuracy / relevancy. That said, there's still value in an approach that allows you to upload a patch and an mp3. Comments for this combination would indicate which guitar the recording was made from.
Even something as simple as a single coil / humbucker designation could be useful. When I audition a tone, I'm looking for a ballpark to see if it interests me or not. A patch labeled "Joe's very cool guitar patch" doesn't tell me whether or not I should spend the time downloading it. If I click the mp3 and hear a clear, bluesy tone and the comments say it was a Strat, or just the xyz guitar on single coil, I have a much better idea of its usefulness to me.
I suggested a third party website (assuming no conflict with Line 6) because software developers in large corporate beasts don't have the freedom or time to do many things they'd like to do. A good idea often meets with Death by Committee. A personal project, on the other hand, has no such constraints and can be whatever it wants to be.
And while I'm grateful for the efforts and sentiments of those who would upload / host large collections, there's no way I'm going to download two thousand patches and hope there are a dozen I care about. With a well designed UI, however, (think Amazon's mp3 previews on an album), I could quickly click and dismiss tones after just a couple of seconds.
All of which is just howling at the moon as I doubt anything like this will appear on the web, either here or from a personal project, but I thought it worth mentioning just the same. You never know...