64-Bit Capabilities are a Default on much, if not all(confused about Celeron CPU's) new CPU's produced by AMD and Intel.
EDIT: My guess would be that that Core based Celerons that would come are 64-Bit capable but Pentium based Celerons are a Bytch to understand on Intel website, more than half are indistinguishable from each other the numbering are almost exactly the same...350, 360, 365??