What do all you Webjay users do not that Yahoo is pulling the plug on the service? One option is Grabb.it. Grabb.it is one part MP3 search/aggregator, one part MP3 bookmarking site and one part XSPF playlisting site. They are also offering a pain-free way to import your playlists (or anyone else's for that matter) from Webjay.
While the in-page player (in the header) is touted as a benefit to pop-up players, I have always found these a bit frustrating. I often find myself clicking away on links while I'm listening and many times the page refreshes on you and stops playback.
Other than that, looks pretty solid for free-range MP3s - but I would like to see some more prominence of the playlists and community.
Other playlisting sites you may want to check out are Musicmobs & Fiql.