Open a support request about phone posting, and die.
I'm sure that there will be far far too many as it is. Trust me, if you know about it, so do 2000 other people. You are not a beautiful and unique snowflake.
(Yeah, that means I have strong indications it will be live soon, which hopefully means it wont' die right away. however, there are about 50,000 people who will have access to it, and even if 1/10 of them uses it, that's 5,000 people calling one poor little computer.)
Ogg vorbis files play in winamp. howto_userdoc post at http://www.livejournal.com/community/howto_userdoc/35472.html#cutid1 has more information on how to get them to play. Linux users, xmms should have an ogg plugin. If not, try mplayer. if not, look for ogg123. if none of those, google and install :P
Why ogg is being used. Basically, mp3s cost money to create. Not for you, but for anyone making profits off them. So, no Mp3s. Maybe later. If people decide ogg really isn't working out. I doubt it. Don't hold your breath.
It's paid account only. No freebies. There will be issues. You can't test, even with an entire development core, as well as 1000 users.