[yuhong]

I wonder why it took until later in 2006 before a version of Pentium M showed up with 64-bit support.

[nilsbunger]

Intel didn't release any 64-bit x86 processors until 2005. They bet so heavily on the alternative, Itanium, that it took them a few years to recover.

EDIT: it was actually mid-2004, as noted below.

[yuhong]

They release the first 64-bit Xeon in mid 2004.