Update:

>> The PA6T CPU paves the way for the introduction of SMP with AmigaOS4.x.

> OS4 core developer tonyw:
> "I would expect OS5 will be 64-bit and SMP."
> http://amigaworld.net/modules/newbb/viewtopic.php?topic_id=33968&forum=33&start=20#622636
>
> Seems SMP got postponed to "OS5".

Hyperionmp says:

"The way in which it will be implemented however is already clearly defined and was subject to peer review by other developers. Obstacles to an efficient implementation were removed (e.g. the use of Forbid) and replaced in many OS components over the years (e.g. DOS).The foundation for SMP support was put in place, a clear picture exists what needs to be done to accomplish it and how. I'm willing to take a bet that it won't take 2 years ;)"
http://amigaworld.net/modules/newbb/viewtopic.php?topic_id=34171&forum=33&start=40#627520