If it was on FSW, they'd have to use a direct kick channel with the FSW graphics, halftime programming, but other announcers. No "red button" option. Same thing with RSNs. It could be done with DC/Metros games, Galaxy/Chivas games, perhaps Revs/Metros and Crew/Fire. Not necessarily every game, though. I'm sure a Crew/Rapids fanzone wouldn't be too popular.
I regularly watch FanZone, it is so good to hear real fans getting on each other. On one of the SkySports News shows around Christmas they showed a best of FanZone and they were all priceless, especially the Newcastle fan who couldn't believe that a shot went off the post. I espescially like the fan saying at the beginning, "Who needs Andy Gray and Martin Tyler?"
Did you hear the NUFC vs Bolton game in 2004, the Bolton guy sounds just like Peter Kay and never shuts up, it was hilarious !!