I've been pondering the 870 a bit. I'm about to be completely wrong here, but I don't think it will come out; not in the form we've been seeing it in anyway. There are a lot of converging technologies and what we've seen in pictures looks more like an experiment to see what's possible.

How far in advance do companies prototype devices, especially to that level of detail? (I mean the first IPod was a printout of the controls taped to a styrofoam block).

What does appear to be maturing is the niche definition that the x70 line falls into. With two slots, that'd give 4180MB of storage (counting the internal 180MB mixed with 2 2GB cards). That's enough for music/movies on the go, with the ability to stream when Wifi access becomes available. If you want 60GB of media with you, maybe the LifeDrive is more to your liking... if you want the essentials, the 870 sounds like it would fit that bill.