There's still one serious issue which is that Intel's initial
foray into mobile is 32-bit. We can't really EOL 32-bit as long
as Intel and/or AMD are still producing 32-bit-only chips.
(Though even in the mobile space I expect things will move rapidly
to 64-bit due to competition from ARM).
Other then that, 32-bit is dead. Even minimalist machines coming
out today can have more than 4G and the larger KVM area on 64-bit
is becoming very important for resource management.
-Matt
