Saying that, a stable Haiku w/ Gallium and proper 3D accel. could well become THE gamers platform of choice- if most the big software houses supported it. Do you want carry on running and patching XP forever? Its not as ridiculous as it might sound as (game) devs always complain about the difficulty of developing for Linux and many flavours of distro and varying 'standards'. There will no doubt be Haiku derivative distros but there will be one, central, definitive base, APIs and standards which Linux has never had. LSB is a joke.
I agree with you fully, and also think that the Haiku platform will take over the open-source desktop, especially in the multimedia and design businesses. The Haiku platform has unmatched performance when it comes to graphics and media in general, since a graphics and sound API is built into and tightly integrated with the core system.
Linux is moving in this direction as well with the new Kernel ModeSetting support as an attempt to integrate the GUI with the kernel, but BeOS is WAY ahead when it comes to this particular aspect of an OS.
The major obstacle in the way of Haiku at the moment, though, is probably compatibility. If someone manages to do things like porting GTK and Qt, integrating PulseAudio with Haiku and writes wrappers for ALSA and OSS, then I believe that more people will consider switching. As it is now, though, this doesn't seem to be happening, at least in the nearest future; even if Haiku gets a few GSoC students to work on it, this won't make any big difference in the long run (just remember how many people are working on Linux projects with GSoC). And how many students are actually assigned to the Haiku project? Something like 6 persons I've heard?