I actually use a similar Dropbox Music setup to seamlessly sync my music via WiFi. I use Android, so sadly I can't check out your app. But it sure looks great, and I would definitely use it!

For those w/Android who would like to use Tunebox -- I use:

1) Music folder within Dropbox, keeps all my music in synch even when switching computers (I use many different computers/laptops, and sometimes my phone isn't in reach but I'd like to listen to my tunes). I have the 50GB plan, my library uses about 20GB of it.

2) The super-uber-incredibly-awesome DropSync[1] Android app which syncs one folder from Dropbox in the lite version. Which is more than enough for me! New music, which I downloaded to my Dropbox on my computer some time earlier gets wirelessly synced for daily use with my phone as soon as I connect to a Wifi. So awesome!

Seriously, I feel like DropSync is the best-kept Android app secret ever. Use it, if you use Dropbox.

[1] https://market.android.com/details?id=com.ttxapps.dropsync