There's been a lot of talk about the N900 Maemo "tablet", especially about how it looks suspiciously like a phone. And even if Nokia (inexplicably) plays it down in their now-official announcement, that's exactly what it is: an amazing-looking handset.
Beyond that Maemo OS we've been asking for on a phone for the better part of a year, the N900 is, as Nokia phones tend to be nowadays, a healthy piece of hardware. It's got a 3.5-inch resistive WVGA screen, ARM Cortex 8 processor, and 1GB of RAM, and is crammed with 32GB of internal memory with a MicroSD slot for expansion, GPS, an FM transmitter, a 5-megapixel camera and a gagillion-band cellular radio, including, crucially, support for T-Mobile's 1700MHz slice of the spectrum.
Since Maemo is based on Debian Linux, the software selection should be interesting. Stock, the N900 will ship with Firefox (Fennec, I assume) and Flash support and an panel-based multitasking system. Maemo is new in a phone context, so there's no way to guess how it'll fare against the other major smartphone OSes in the real world, but it sure as hell looks a lot more exciting than S60, for what it's worth. Nokia: Maybe not doomed!