Damm you guys a sharp :-)
I am first of all thinking of a OS3.9/MorphOS dualboot setup. I had a A4000D+PPC setup a year ago but sold it to get a PegasosII. MorphOS was nice but the Pegasos just wasn't me.
But I sure also do hope that OS4 will support G-REX. But as you all say: We don't really know - yet.
Well. In either case the wait for OS4 is soon over - I hope.