The Amiga's abilitly to run multiple program windows at the same time for low memory useage has allways been impressive.
Given that the screen shots were taken off an A1 800mhz G3 with 256mb certainly shows that OS4 certainly appears to be following that tradition.
Its a pity though that three of the programs you show in screenshot namely Jabberwocky,I Browse & Amiga Amp don't seem to have moved on in appearance or increased functionality from the versions I have run on 3.9 for the last two years
That though is a critisism of the above 3 programs which compared to the rest of the desktop appear "clunky" by comparison & for demonstration purposes of OS4 may graphically draw false impressions.
The need for better applications is going to be the real deciding point if OS4 is going create new converts, so the IMHO news on this front will I believe inspire more desire to give it go.
As a suguestion perhaps the better skinned Frog or Toad players would fit in more with the screen shot styling than the now "old looking" amiga amp WINAMP lookalike ?
That or if your just wanting to show it's improved music functionality a more impresive Amiga Amp skin
As a PPC user I await news on it's eventual porting & subsequently hope it will bring more with it than just the FIRST impresion of a better looking desktop