> People who like to play 3d arcade games from the 2000's emulated in MAME still find > x86 performance relevant, but even for them, it's only a handful of games that don't > already play at 100%.
Not quite. Pure performance still matters for a lot of "workstation" type stuff, including programming, scientific work and 3D content creation.
And I think next year you'll start seeing new PC games that no longer support XP and hit CPUs a lot harder as a result (because machines with Vista or 7 on them are essentially guaranteed to be at least 2007 spec).