The crap SSD long ago died so my machine now runs LXDE off of a USB key, but it's still chugging. Still even gets 4 or 5ish hours of battery life which is pretty damn amazing after sitting around that long.
I keep thinking at some point someone will make a 12" cheap device with a day's worth of battery and maybe keep it completely fanless.
But no. The only thing remotely close any more are chromebooks, which lack the hard Linux features that make my netbook so useful. Unfortunately everyone else just price gouges you for something with an i3 that mysteriously costs $600.
As for Ultrabooks... they are HEAVY. Every time I see one I think they look great until I pick one up and it weighs ~ 2.5 times what my netbook does. Go figure... One of the things I love about my netbook is that I can hold it up with hand all day.
In any case, I don't think they're dead. Marketers just figured out how to label them ultrabooks and get an extra few hundred dollars.