I have to say that the excitement disappeared as I watched it. I really wanted to like what I was seeing, and not nitpick the differences from the books, but the CGI green martian in the clip looked terrible and the aesthetics struck me as more "Prince of Persia" than Barsoom. It also looks like they felt the need to transform Dejah Thoris into a D&D warrior-babe given the brief clip where she's armed (as they did with Arwen in Peter Jackson's Lord of the Rings). Not that she was helpless in the novels, but she wasn't a warrior either. Ugh.
Seeing this did inspire me to re-read the books, though, and they made a pleasant, light read. Although I found them a bit repetitive second time around. Still, thanks to Kindle, you can't go far wrong with $0.99 for five novels: