If you're thinking of buying the pogo, you should know beforehand exactly what you're getting.
As it currently stands, the printer is more of a fun/arty toy. I have a polaroid izone, which was great fun when I was able to get film for it, and if you've ever owned one then you'll already have an idea of what to expect. The pictures aren't large (2x3 inches) but I really like that, they'd be a perfect size to keep in a wallet if you wanted. The sticky back is handy, and I've found that it won't peel paint from walls when removed.
The cost of paper means each picture should average between 20p and 30p, the cheapest I've found works out to 21.4p each.
The printer itself is larger than I expected at roughly 120 x 71 x 23mm, but that's still a very manageable size.
You shouldn't buy the Pogo if you want professional quality prints; the colours aren't totally accurate (in my experience, dark red/brown may come out a little pink-ish and in most cases colours won't be as vivid as the original) and although I don't know the exact DPI equivalent, it's certainly not going to rival a photo printer.
Depending on why you buy it, however, these points may not actually count against. The quality of Polaroid photos was always a little different anyway, that was the cost of immediate images and this printer is no different. I actually like the colours being a little abnormal, it seems more authentic.
Bare in mind that since the colour reproduction is reliant upon the paper rather than the printer, there's always the possibility that Polaroid will bring out new paper and maybe even firmware updates to complement it, though that's entirely speculation.