Linux has traditionally maintained support for older hardware - through driver support, forums to answer questions, and Linux installations that are snappy even on old hardware.

Actually, I see desktop computing (including laptops) hitting a plateau already just from being good enough (factor in Windows XP's decades-long lifetime).

Arguably if desktops are plateauing, embedded devices will follow a similar trajectory on a shorter time scale - all the hard-knock lessons are already known.

Ultimately the year of the Linux desktop won't happen - but businesses will face fast-shrinking margins for desktops, laptops, and per-seat software licenses.