http://hardware.gamespot.com/Story-ST-11721-1386-x-x-x
As with online play, work on the ability to download PSP games will have to wait until after the official US release. EA associate producer Joel Manners says that downloads are a great way to offer extended content, but he's more excited about the ability to offer new game demos to users via download since it's "the best way for a good game to get out there is to provide it to folks and get in their hands." EA won't offer any downloadable game demos at launch, but, according to Manners, "it's something we're very, very interested in doing."
The game download model also hasn't been revealed yet. Publishers might be allowed to distribute their own files, but it's also possible that they may have to send them to Sony for online distribution. PSP users, of course, will benefit either way as long as the actual "download now" link exists somewhere online.
The Sony PSP's 802.11b wireless capabilities should allow users to access other the internet though a wireless access point such as a home wireless router much like how console connects users online. However, according to game developers we've spoken with at CES, Internet multiplayer capabilities won't be available in time for the PSP launch in North America.
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While Sony hasn't given official word on the official timeline for the online multiplayer rollout, Oertel feels that "anything that can extend the gaming experience to other users is a good thing" and "as with any new hardware, I'm sure very dedicated users will find unique ways to enhance or utilize the technology in new ways." Dedicated user groups are already developing "tunneling" programs that allow PSP users to play against each other over the Internet.