It was first mentioned back in October, but I just noticed the TAZ I from Tight. in a banner ad on Gizmodo today. The specs are quite impressive, and it's been mentioned awhile back.
It has a removable HD and a dockable, removable "mini-player" to go. The device supports MP3, OGG, and APE audio and MP2, MP4 and DivX video. It also supports HiDef output. Also sports on-board 10/100 ethernet (interesting - for streaming stuff? WiFi would have been cool).
And a Flash-based interface, which I bet is pretty slick.
I think the removable mini-player is a neat feature, especially since these things are getting bigger to accomodate bigger screens, batteries, and processing power.