Just finished listening to the latest show, and I have to agree with you 100% on your review of Tron: Legacy. I was supremely disappointed by the film, but I think part of the reason was that I had absurdly high expectations (I saw the original Tron at that perfect age that makes it impossible to view objectively). I'm even more looking forward to True Grit now so that I can reassure myself that Jeff Bridges is indeed capable of playing a character other than The Dude ("You're messing with my Zen thing, man." Seriously?!?)
I'm glad you pointed out Ed Dillinger, Jr's complete lack of anything to do in the film, because that bugged me too. The movie was full of winks and nods to the nerd types who remember everything about the original and came to the screening I attended in things like Spider Man sweatsuits (to be fair, I fall somewhat into this group too sans super hero garb). Things like "ooh, look! Sam lives in a garage that says 'Dumont' on it!" were cool for a little while but became annoying when they didn't actually mean anything. The biggest offender to me in this category was the character of Clu. When I first heard that Clu was the villain of the film, I thought it was neat because apparently some part of that program Flynn wrote in the original was retained after being destroyed by the MCP, and I was curious how that would have worked out. Sadly it turns out that Flynn just likes to name ALL of his programs Clu.
Another missed opportunity was the whole open-source vs. closed idea. At the beginning of the film, Sam releases the new Encom OS over the internet making it available to everyone, apparently as a way of giving the finger to the idea of making a profit off of it. Towards the end of the film, Clu makes a similar statement in his speech to his army (whatever happened to all those guys, anyway?) about how he was making the world accessible to all. Was this an intended parallel, or just sloppy writing? I have to guess the latter, because I get the feeling that the filmmakers couldn't have been bothered to explore a concept where the hero and villain had similar ideas.
In the end, I agree with you in that it's a perfectly fine disposable movie. The original had the wow factor in that people had never seen anything like it before, so it could get a pass on the story problems. This time around, though, while it looks cool, there's nothing really novel about what they're showing, so the flaws in plot stick out that much more. Kind of like the original Matrix compared to the sequels for me (right up to the lame resolution for both).