Re: 64bit?
Yes, the atom is 8 times cheaper. But on the other hand, the server need 10 times more CPUs to workout the same amount of workload (There is a comparison between Xeon and ATOM in the article). So, after all, Intel will earn more money if you choice the ATOM. There was a comparison between Xeon and claxeda ARM.
http://www.theregister.co.uk/2012/08/13/xeon_vs_calxeda_arm_apache_bench/
It can be see there by deploy the micro servers, company will actually spend more money on the server to cover the same workload.The benefits of microserver is that when the workload is I/O bonded or server is idle, the server saves power.