n900 is a phone. You're thinking of the nx-71 (I think that's what we've settled on is the next possible device prototype ID) which is due late this year. Announcement is rumored to be coming this month, but I'm holding my breath and expecting more like a Q4/09 or a Q2/10 announcement at this point.

As for them running out, it's likely that they simply ran out of stock on the last run. If the n810's last run sold good enough, they'll do one more run, but that's likely it. Although I wouldn't hold your breath.