None of the rotary sticks currently available have their own interface, USB or otherwise. You could drive the rotary functions on a pair of Happ optical rotary sticks with a single USB Opti-Wiz, Opti-Pac, or Mouse Hack. The regular directional functions hook up through a normal keyboard/gamepad encoder, just like a normal stick. MAME defaults to this type on control, so there's considerably less fiddling to do with making it work. It's the easiest method currently available.
Of course, the optical rotary sticks won't "click" into position like the mechanical rotary sticks you used on the original games. Mechanical rotary sticks can currently be interfaced with a Druin's interface or the Ultimarc Rotary interface to handle the rotary functions, and the regular directional functions hook up through a normal keyboard/gamepad encoder, just like a normal stick. MAME needs some special fiddling to make this setup work, and it is not always click-for-click accurate, or at least it was not the last time I checked.
Whichever route you choose, the Happ rotary sticks are built on a Happ Super base, so either will be a drop-in replacement for you current Supers.
I believe RandyT has stated that the new sticks will be 49-ways with a rotary function. I think Happ 49-way bases fit the Super mounting holes as well. My bet is that the new GroovyGameGear sticks will use a mechanical rotary system , and I'd also bet that they have their own on-board USB encoders for both the rotary and directional functions, all in one unit. Hafta wait and see on that one, though.