Hopefully somebody at Muppet Wiki can come to University of Maryland sometime in the near future and look at the season 11 and 12 guides (and remaining season 10 guides, if there are any). At this point there'd probably be episodes that featured Leslie Mostly, Dr. Noble Price, Deena and Pearl, and Warren Wolf, as well as the start of episodes with Bruno (depending on whether he would be mentioned in script highlights for scenes he appears in). I particularly wonder if any of the season 12 guides up there can clue us in on whether the "bring your own can night" segment was an insert or part of a street story. It'd be interesting to finally see EKAs for Deena and Pearl sketches.
But then again, is the stuff found in these scans from the CTW Archives? I wonder how it's all been found here (did Danny or somebody with scans put them there? Did the University of Maryland provide them?).
I guess I shouldn't be surprised if the program guides indeed went past season 12 (and I know Oscarfan didn't specifically say they did, just guessed). Somebody at Muppet Wiki has Japanese program guides for episodes from the late 1980s and 1990s (and a selection of season two guides). Of course those are different from the American guides, as they appear to be complete rundowns of the Japanese broadcasts of episodes (well, the season two ones aren't).