I'd say the technology hasn't quite gotten to the point where it needs to be for a general purpose pocket computer to really do what people need it to do until now.

Intel's certainly pushing MIDs, Microsoft has Origami, and there are several companies pushing extremely powerful ARM SoCs that fall outside the range for smartphone devices. The big players see the potential in the market segment even if you don't. The netbook's dominance will be short lived. People don't want smaller laptops, they want something that fits in their pockets, and smartphones just don't cut it for browsing Facebook.

Nokia's broken into the market, now they're ramping up to watch it explode.

The form factor may be similar, but the guts aren't even remotely comparable. An OMAP3 tablet is in a different universe from an OMAP2 tablet. It's got the guts to provide a smooth web experience, to be a powerful media player, to run those 3D games, and generally do everything one would expect a laptop to do, but also fits in your pocket.

. . . and what's preventing the Maemo 5 device from being that, too?