While workstations for developers have bigger and completely different
requirements, in general the most demanding applications for ordinary
sixpack-joe are hd-video transcoding (which actually isn't memory
intensive), image manipulation (this year's basic $100 models already
sport a sensor of 14 megapixels => 45 MB per image layer), and
surprisingly web browsing.
The ARM equipment support this by providing powerful co-processors and
having a tiny (Thumb) instruction set. It's really hard to see where they
would need more than 4 GB of RAM.. even according to Moore's law it will
take at least 6 years for the top of the line products to use this much
memory.
but they work on 64bit:
http://www.computerworld.com/s/article/9197298/Arm_readies_processing_cores_for_64_bit_computing
