You're right about there being a slew of bluetooth devices out there. Some of them cost a few meals; some of them are free; most of them are pretty nice; all of them are pragmatic. This hack was written in the spirit of empowering/educating others, having some some fun, and "getting inside" the design of something like this.
I'm very much a pragmatist myself, but often find myself trying to avoid it because it can usually be more fun and interesting to homebrew something.
I know that at least for me, bluetooth devices often seem to have a little less range than that 30 feet that's advertised, and the concepts from this piece can be taken in a lot of other directions.
Just a fun example of that: you might be out on a date and use your cell phone on the way back home to turn on/dim the lights with some of that cool light controlling hardware that's becoming affordable these days, start up some music with iTunes, etc.
It's all fun!