There was a rumor about a month or two ago that had Smallville wrapping up it's production in season 9, followed by a theatrical release of a Metropolis as a "final finale" to the series. Many balked at the idea as, while cool for fans, probably wouldn't have the mainstream appeal. I've recently heard that it was, as you mentioned, a made-for-TV movie, which sounds more plausible. There was also a mention made a few weeks back that there would be big Superman movie news revealed at the Comic Con. Perhaps all this is tied together.