[Cialug] 64 bit difficulties?

[Nathan C. Smith]

<snip>
I'm using Gutsy Test release, which as I understand it, atm is closely
tracking debian unstable. I'm having excellent luck, and except for the
usual "unstable" issues (doing an update might break stuff for example), my
computer is working better now than it ever has. 
<snip> 

Is there a difference between 64 bit on AMD and Intel?  Are all dual-core
systems necessaritly 64 bit?
 
-Nate