It sounds like this would be a lot more efficient than our current system. I'm sure locking topics in Submissions or moving them to Sprite Discussions on a daily basis for the exact same reasons (bad sprites, content that wouldn't be accepted in the first place, etc.) is incredibly taxing, annoying, and is a waste of time; whereas, this system is a really simple upload form that's easy to understand, and is easy to operate (on both ends). But just to be sure that it would work out well, it'd probably be a good idea to give it a test run like Badassbill suggested.
I have one question, though. If people post a topic in the Submissions board looking to get their sheet submitted (and let's say it's a sheet that would be submitted), what would happen to the sheet/topic? Would the topic be locked with a post informing the submitter of the new way to submit sprites, or would the sheet be accepted through there like they always have been? There's a chance that you'll still get people that submit sprites through that board, which could result in nearly the same amount of work.
I have one question, though. If people post a topic in the Submissions board looking to get their sheet submitted (and let's say it's a sheet that would be submitted), what would happen to the sheet/topic? Would the topic be locked with a post informing the submitter of the new way to submit sprites, or would the sheet be accepted through there like they always have been? There's a chance that you'll still get people that submit sprites through that board, which could result in nearly the same amount of work.