I am probably more a tech enthusiast than most here.
This will allow the device to be sleeker and more sturdy. It's a portable device and I think removing moving parts is a good idea. It's good for a better battery life, making the device slimmer, less wear issues in course of time, better loading times / higher tranfer rate for streaming and you don't have to worry about carrying storage media with you.
IMO it's the way of the future for handhelds and certainly a much better approach from a technical perspective for long term potential. For retailers it may be less interesting as they will probably only carry PSN code cards for credit.
Broadband internet is also a good idea, the popular iPhones and Blackberries have paved the way for improved coverage. Online gaming can thus become more advanced on handhelds.