Actually, there's been
research (if thats what you wanna call it) underway for some time to create the varitable "VR Porn" suit. Imagine, wearing a full body suit with
lots of neat pressure zones (Especially "down there"), sensors, etc. which would react to stimulas you trigger by interacting with your "mate". I think they were referred to as "ErosWare" suits. As for the actualy perceived environment, I would guess something along the lines of a goggles and an internet connections to your 'partner'. Imagine catching lag pockets during climax...It's real wacky, y'know...
For now, I figure it's still very
experimental, I'd say give it ten more years...