Intel Atom CPU - 32 or 64 bits?

I've been installing the latest test releases of openSuSE (11.2 Milestone 8) and Ubuntu (9.10, Karmic Koala Beta) on various of my computers. As the new HP Pavillion dv2-1010ez has an Athlon 64 Neo CPU, I started paying a bit more attention to when and where I could install 64-bit versions. The ones that turned out to be interesting were the Atom CPU systems - the ASUS N10J netbook, with an Atom N270, and the desktop mini-server with an Atom 330. It turns out that the desktop versions of the Atom CPU (230 and 330) have the 64-bit x86-64 architecture, while all the rest have the 32-bit x86 architecture.

jw