"That is a extremely optimistic version of the Linux graphics story. While open drivers for intel,ati and nvidia exist, the window of RELIABLY working hardware is sometimes incredibly thin. Too old chip (Intel 855GM was really buggy around 2.4..2.9 versions of intel driver) and support is spotty."
Wow. That's old.
"Too new (GMA500) and no support at all."
New _Intel_ chips are supported just fine. GMA500 is not Intel chip, it's licensed Poulsbo hardware.
"Nouveau works really well only between NV30<->NV50."
Who cares about earlier chips? And work on the recent Fermi cards is already in progress.
"I would assume ATI has the same issue of code supporting old HW getting bitrotted and new HW support not being ready yet."