Earlier, I was wondering if the new G5 Macs would have an OS that could take advantage of their 64 bit nature, or if Apple was going to take a short cut and run the G5 in a compat mode. Apparently, that is going to be the case, at least according to this Register article.
In a lot of ways, this is just more hype from Apple. Many Intel processesors (I don't know the exact ones) actually have a 36 bit addressing bus. Those extra 4 bits mean that the processor can actually address 16 times as much memory as a 32 bit addressing bus. The difference is between 4GB and 64GB. However, most Windows machines don't take advantage of that extra capacity. The APIs are there though, if you want to use them.
So, is the 64 bit nature of the G5 hype? As far as I can tell, right now the answer is yes.
(Well, I'm sure that someone will port 64 bit Linux to it, and that will be cool. It might become the cheapest way to get a 64 bit linux machine, if AMD doesn't beat them to the punch)