Well this is the second little visual prank Elbox has played. I'm not impressed. They should spend their time getting somebody who is fluent in English to communicate with the public so that Elbox can understand what we're asking them and then give us answers that actually are worth something. The email replies I got from them were pretty useless, sad to say.
As for being "limited" to 3.9 -- AROS is supposedly being extended to embrace 3.9 and move it forward. IIRC.
And there was the recent Hyperion chat where there was uncommented banter about OS4 for "classic" Amigas.
http://www.amiga.org/forums/showthread.php?t=46389 There's also something called AFA OS3.91 which uses AROS to extend 3.9.
http://www.amiga.org/forums/showthread.php?t=46385and here:
http://amidev.kilu.net/afaupload.php3As the person involved isn't fluent in English, it is a little hard for me to understand.