I'll give TRON: LEGACY another shot. I have the double-feature Blu-Ray at the house. I didn't like the film when I first saw it in December. I think the film's got too much fat on it, and in comparison with the ideas of the original film, I thought LEGACY didn't add much to the table. But I'm willing to see it again and reassess it if the film warrants it.
Harry's said for months that another sequel will probably happen, and according to Deadline, since T:L broke box office records for first-time director Joseph Kosinski, it looks like we'll get another go-around on the Game Grid. Kosinski would likely return, along with LEGACY screenwriters Edward Kitsis and Adam Horowitz.
I don't think they'll get the budget they received for LEGACY, so I'd imagine the story should wind up much tighter. The original film, in regards to pacing, is practically a Swiss clock in relation to LEGACY. I liked the idea of the ISOs, sentient programs created without User input, but the film didn't do anything with it. TRON's imagery may seem retro today, but it at least had more colors than blue, black, and yellow. Eh, don't get me started. Harry told me he felt like LEGACY was a "middle" film, a transition between the original and the more complicated computer ideas of today that the third film will likely portray. I'll watch it again with that in mind. I'm still a huge fan of the original film, dated as it may be, and I'm glad I got that film on Blu-Ray, at least. If the third film touches upon the Internet, and the expanded universe we all share, it could very well be amazing.