Gaming firm Rockstar has announced that GTA: ChinaTown Wars is to be launched onto the PlayStation Portable. GTA_CTW_PSP_01 GTA: Chinatown Wars is coming to the PSP Set for release this Autumn, the latest version of the previously Nintendo DS-only game has undergone several changes in order to bring it up to PSP quality, …
Clearly you don't you get it..
"The title will be available to buy either through download or on UMD - which seems, perhaps, odd given the UMD-less PSP Go is set to go on sale in October."
Clearly download option will be for everything moving forward, and UMD will be in addition for the forseeable future, as whilst ALL PSP's can use the download option, most consumers still want physical media.
Making a game like this download only would be suicidal at this moment in time. (however it would still outsell the DS version, which flopped dramatically because DS owners only like Mahjong and Soduku games).