I know they say "just use the thanks button" for these types of things, but I have to thank you with words. Mostly because I have a ton of WP7-toting friends, and we'd all reach for our phones when one of them went off due to the limited sound set. I've mostly averted it by sticking to the Nokia sounds that come with the Lumia 900, but they're upgrading to Lumias now, so it's not going to work for much longer.
Just have to wait for an interop unlock now (and I'm pretty sure it'll happen since the Lumia is a pretty popular phone it seems)
Stay tuned, new features will come (sound modifier and more)