What is the point of 64 bit Squeak?  Is it the same as the point of 64 
bit processors which is (as I understand it) that they can address more 
than 4 gigabytes of RAM?  Or are there other benefits besides the 
larger address space?  Would there ever be a reason to prefer a 64 bit 
architecture over a 32 bit one for applications that are known to fit 
in less than 4 gigabytes of RAM?