I agree the phone is still "on paper", because I'm working 100% on the Moto Keyboard Mod at the moment. Moto Keyboard Mod has working prototype and we are working on final units for certification and launching. You can see on twitter @LivermoriumLtd It's not vapourware.
In my opinion the GPD people got one thing right (in contrast to the Gemini people) and that is providing a trackpoint.
I confirm the GPD Pocket is not perfect, but it is very nice out of the box. I have already begun testing various distros to get a handle on it. Having a keyboard again is like being back in paradise.
The Purism is a very hopeful direction, but as I alluded to above, if the hardware needs a specific software then this locks out Linux solutions already coded and ready to go. And makes creating new solutions a headache of learning new integration steps.
It (GPD pocket) 's a great little useable linux box. e.g. Last night I was working on a Mathcad calculation in WinXP in virtualbox on it, while sat in front of the TV. Also scribbled a couple of short python scripts and ssh into a couple of other machines. Battery life is great - I was at 75% after probably 3 hours use. Lots of times I wouldn't bother dragging my laptop to customer visits unless I anticipated wanting it - I will certainly have the GPD along in similar situations now though. (I won't be leaving it datalogging inside a lamppost overnight like I do my Toughbook though )
Gemini - seems it should be much more pocketable than the GPD. I was initially skeptical it would end up with a linux distro available, but that seems more likely now. Great pedigree on the mechanical design. If I had written an ideal device spec before this existed, it would have been close to this... Psion5 mechanics and form factor are probably as close to perfect as I can imagine.
Neo900 - Reusing the N900 mechanics is too limiting IMHO, even if it had arrived in a reasonable time. To work at all, it would have had to be a drop in replacement while N900 owners were still using their devices daily en masse. Now it would just feel a step backwards, even with brilliant hardware behind the screen.
Pyra - haven't been following this one, other than it seems to have been 'around the corner' forever.