Did you know Jeff had 3D accelerated Amiga hardware running on the Amiga 10 years or so before the PowerVR and 3DFX cards appeared on the PC, but Medi Alli (sp) said nobody would ever pay for 3D accelerated hardware... lol.
Also the third-party-firms which did video-cards for the Amiga were not interested in such things. I remember walking with a friend of mine over the amiga exhibition in cologne and asking them after 3d acceleration. They were looking at us like we were aliens...at least that's what i would imagine how aliens would be looked at like. ;O)
And as for workbenches: http://www.gregdonner.org/workbench/
Greetings,
taumel