H2H is dead, and will never come back. Its simply too big a security hole for HTC.
Its gone, and its never coming back, EVER.
What will come back is user configurable arena's. They will be run on HTC's server, you'll go through HTC's password server to log in. That way they maintain control.
Hopefully they can be password protected. So if your planning a squad meeting only those with the password can get in.
There is no hard number on how many it will hold, but the general feel is quite a few more than H2H. Pretty sure you'd be able to have a 8 vs 8 duel, Possibly a 16 vs 16.
User would have all the controls he had in the old H2H. But, terrains would have to be approved by HTC in advance like the skins are now.
So the bare minimum required is going to be to have an active AH acct.
That way at least you have something to lose.
No one time fee's, no freeloaders, if you want to play sign up.