An acquired taste. For me, someone who has no knowledge of computer programming and the sort, it's a very slow, tedious and boring watch.
'Tron', unfortunately, didn't take my interest whatsoever. Not helped by the poor special effects (they get a pass due to it being an 1982 release; though I'm not convinced it's good either way) and forgettable cast performances, it's not a premise that's easy to get into if you have no prior understanding of coding etc.
There is some intrigue in there, but not nearly enough to satisfy my viewing pleasure - it felt like a much longer run time than 96 minutes, that's for sure. All cool if you love this, but I very much didn't. Hopefully the 2010 sequel gives the concept a major boost.