While normally listening to people kiss the dev's collective ass makes me sick, I feel like I've gotta comment on that one ..
Firstly, one of the best things about open source projects is that IF a dev loses interest, or concentrates on real life or other projects or whatever, you can modify it yourself. Cant program? Learn. And if you're not willing to learn you're in no position to critisize those that are on their lack of interest.
Now if it was a dead project with CLOSED source (and as far as I know Stepmania-X is neither) I'd be a lot more concerned. Nothing more frustrating than knowing that theres never gonna be any more updates to what should be a great program.
This post has come off a little more negative than I'd hoped, please keep in mind it is intended as a general statement and not a personal attack