I think this would be awesome.
There are a lot of really good melee players on NA, and people that just generally enjoy melee fighting. It would be nice to be able to fight without having to look out for arrows flying through the air and horses coming to trample you. I think it would probably get at least ~30 players most of the time, and more at peak hours - probably more than the ATS Community server. I'd definitely play it.
Edit: In fact, even if my main was an archer or cavalry build, I would make a melee fighter alt for duels and the melee server I. Skip the fun is there for a reason, right?