
Being a BeOS user (a purely desktop system) and because I code under Linux, I see
XFree86 (v4.1 on my machine) as a user and as a developper. And this is where the problem lies. My Gnome or KDE desktops are slow in comparison with other operating systems, but XFree86, the 'engine' behind these desktops, proves me that it's not. Let's look at what I have in front of me: a dual Pentium III at 933Mhz with 512MB of memory, a Radeon 32 AIW, a modified Mandrake 8.0 powered by kernel 2.4.18.
Sorry, but the original BeOS will die because it will not have drivers for future hardware.
http://www.yellowtab.com/ - BeOSr5 developed further and will be shipped with alot of new drivers
http://www.bedrivers.com/ - BeOS driver development
IMO, yellowtabs Zeta may keep the die-hard BeOS users until OBOS becomes an option.
People going to Cosmoe/Blue will probably be mostly linux users - often with some previous experience of BeOS