10 Mbits/s with a mobile phone

NTT DoCoMo demoed 3 prototypes of cellphones based on the HSPDA norm (high-speed downlink packet access). This norm also called 3,5G will allow reaching theoretical speeds up to 10 Mbits/s.
As the name has it, this norm might be implemented without replacing the UMTS equipments which have cost so much to install.
Still there is the usual question : what good will such a speed be on cell phones whose screen size and capacities will necessarily be limited?