Now, quite fed up of waiting, I'd like to know if there is any reason to buy this new SAM system
If you want to run Amiga software you're better of with UAE or a real Amiga.
If you think you might be interested in OS4 software, just go look at os4depot.net, that site hosts most of the OS4 software out there. First thing you need to realize is most "OS4" software is just ports from other OSes. There are a handful of commercial packages for OS4, the most notable being Hollywood, the rest isn't anything special.
It might also be worth reviewing the history of the past few years of OS4 developments, just to get some idea of how likely (or not) the kind of software you want is going to become available. Since you mention 3D work, you should be aware that DiscreetFX bought up Aladdin 4D a couple years ago and claims they'll be making an OS4 version. Also there is a version of Blender kicking around (unfinished I think), but then you can run that on anything.
