I've just bought series 1 on DVD today (in Holland, Europe). Even though the release-date should be a few days later, I noticed it in the video rent store.
Ofcourse it's Friends and thus worth the cash, but there are even less specials on the discs than the series 4/5 dvd's (only the music video from the rembrandts), and the picture quality sadly isn't any better than the series 4 DVD set (SVHS at the most). In this respect, it's disappointing since they could have at least worked on the quality of the video.
Bram