Many of the specific cities haven't been picked yet, but there's been a lot of talk about it in the past few months. Basically, with Notre Dame making the move to a 12-game schedule, the decision has been made to make the 12th game each year a neutral-site game played in scattered locations all around the country. There's been a huge deal of speculation about both potential opponents and potential locations, but very little has been set in stone yet, at least from what I'm aware of. This has been discussed on several occasions here in the forums in the past, but I'm too lazy to dig up the thread links.
On a related note, Tommy, since the neutral-site plan seems to be news to you, this probably is too: as part of Notre Dame's agreement to play several Big East schools each year, ND is in serious talks for a home-and-away series with... drum roll, please... USF. Right across the state from you and me over in Tampa. The idea would be to expose Notre Dame more to Florida recruits, while USF gets a big publicity boost for their up-and-coming football team and a nice chunk o' change. It's not set in stone yet, but lots of people have been talking about it on-the-record, and all involved parties seem to want to make it happen.