As I have TGP on the 2-disc Collector's Edition, I was interested in trying the Blu-ray. After a bit of research I found that the US Blu-ray is listed as Region A, but it is also Region B compatible, so I took a chance and ordered it - from All Your Music in the States - and after a quick delivery time of nine days (for trans-Atlantic post: ordered 29th Nov, delivered 8th Dec), I've just tried the disc out on my UK-bought Playstation 3 - no problems!
One interesting thing, which was a bit of a shock, was the English dub - this is not on the DVD, and differs from the translation subtitles from the DVD, which may annoy some. When I get time this will be an interesting watch...!
Picture quality. Well, after checking a few scenes, it's an improvement - in places; almost too much as the prosthetics are a bit obvious at times. Maybe because I sit closer to my monitor (PC/PS3 plugged in) than I do to my TV, I noticed some instances of not-entirely-HD-quality, but that may also just be the film and it's low budget origins. For example, some shots of the Crocodile Girl are soft focus and others are pin-sharp, but her attack/posing are pretty much sharper than the DVD.
The extras disc is a DVD - probably Region 1 (from hints thrown up in my research), I haven't tried it - but it only contains the short insert films/adverts from the film, which for some reason are not on the Blu-ray. Odd, as a Blu-ray has quite a bit of space available...!
So, to sum up. If you want TGP on Blu-ray and have been put off by Region A notices, fear not. Mine is UK-compatible, so yours almost certainly will be. Go on, get yourself your very own Crocodile Girl for Christmas!