Well I'm curious as to how the idea came about. Way I see it I think you may have gotten the idea by looking at conversations that might tend to flow on a forum like warez bb. But actual downloading for most people would work like this. Person sees link. Waits for 30 seconds for it to be available and then sets it to download and continues with whatever they might be supposed to be doing.

So here come the questions 1) are you solving a problem? Or is this a novel idea you think might be cool? If it's the former then what is the problem? If it is the latter the next question will be even more relevant 2) typical file share downloads won't last more than 15 minutes. Minimum a minute. Average somewhere around 4 minutes. Why would people want to chat for that time? 3) given that people set stuff to download and move along you have to be adding value to what peoples time if you expect them to devote time to chatting instead. What's the value you add?

I will never shoot down an idea outright so go ahead and answer without worrying that I'll cream over you. But you do need to be able to answer those questions to anyone to say why your idea is actually something that would be worth using.

Cheers. More questions after your answers :)