@CroCrew
OS4 itself is being worked on full time by a small team of developers, and part time by a larger group of developers. The OS4 team wouldn't continue if they didn't have plans to get OS4 out there on available hardware in the near future.
There are two publically announced projects to bring out PPC hardware for OS4 (ACK and Troika), which a lot of people are very skeptical of (understandibly), and the OS4 team have hinted at other deals in the pipeline.
Basically, a lot of people think OS4 is now totally dead, a lot of other people don't agree.
Welcome to the Amiga world ;-)
Personally, I'm a beta tester and I can see for myself that OS4 development hasn't stalled (there are still new updates nearly every day for betatesters). I also have a bit more faith than most that Adam (the guy behind some new OS4 hardware) will actually get some hardware out, but i'll leave that up to you to judge.
BTW: MorphOS is kind-of in the total opposite situation; hardware is out there and available, but the next major update to it (1.5) has been "due for release any time soon" for quite a while now, and a fair few MOS users have totally given up hope for it to ever appear. But there have been a lot of small updates released, as well as unofficial updates from end-users.