SoundCloud is almost ready to unleash a completely new version of the site, which it very originally named Next SoundCloud. The new site is in private beta, but you can request an invite.
It's a complete revamp and there's plenty to like. One very nice feature is a new persistent player which enables you to browse the site but continue to listen to whatever you're listening too.
The iconic waveform player has been redesigned as well, keeping the waveform but using HTML rather than Flash for everything.
You'll also be able to move faster through the site, or control the songs, with keyboard shortcuts. On the social side, you can now "repost" tracks or podcasts from the people you follow, helping quality content spread virally on the site.