Even though the movie faired poorly in theatres, it seemed like the Speed Racer sets sold pretty well--in particular the two $20 sets of the line. Speed Racer was a big deal in the early seventies which prompted many an AFOL sale, no doubt. Unlike some other licensed themes, it didn't seem like Lego had that massive of a production run of the sets. The simple fact that Lego was a hot selling toy caused a rising-tide-lifts-all-boats effect as well. Granted the truck was a lousy design, but most kids like race cars. I think some of the sets ending up in clearance was because Lego always viewed it as a brief theme and wanted to make room for the upcoming batch of Clone Wars sets.
The POP sets I think will sell well. They do look well designed as well as different from many of the current line up. My six year old is obsessed with getting a set simply because of the dual sword factor. I don't think the movie will break any records, but kids are so hooked on Lego these days that almost any theme will sell well.
It's too bad that Lego didn't pick up The Last Airbender again. The two sets they released before were pretty nice. Unfortunately the cheaper of the two sets was $30 which was a bit steep as an entry point in the line.