I don't see TM being a single. Honestly I don't see anything past the 3 that are announced. Any more and you're going to have half the album out as a single. And not all bands release the ballad as the last track.
Eh, what does it matter. Like someone said earlier, the most important thing about Iridescent being the next single is not how it charts but the video.
Iridescent is probably next. They were going to use it or Waiting For The End as their first single but instead used The Catalyst. Iridescent was a featured track on the retail version of ATS, so I doubt it would be something else.