I think you should channel your knowledge into something else because you don't stand a chance against iLike, Facebook's almost-official music application. You will also have a lot of trouble getting artists to pay you anything when MySpace has long been established as the place new wannabe superstars showcase their talents. When you add to that Google's almighty YouTube, new artits have a whole range of free, well established, well known services thay can use for free to showcase their talents.

Bare in mind I haven't yet mentioned MTV's Directory and specialist services such as GarageBand, SoundLift, RecordScout, etc... and those are only the top results I found on a Google search for "upload mp3".

You idea is achievable, maybe, by a large team of experienced professionals. Your "one man show" hosted by Heart Internet (which BTW, aren't great) doesn't stand a chance and will definitelly be a waste of your time and valuable knowledge.

If you want to do this as a personal project that nobody will ever use, go ahead. But if you want this to be a means of earning some cash, you have to channel your expertise into something else.

IDEA: How about creating a service where you use your expertise to help new artists? Provide free information? Charge for consultancy (rather like an agent)? Your knowledge is valuable and with the right website (attractive and informative) you could establish yourself as an authority in this VERY popular field and then, only then, convert your traffic and popularity into a business.