Sony released a new firmware update for the Sony PSP just a couple of days after it released the last one.

On June 24th Sony released the firmware 3.50 with the faster CPU option. Today the company released firmware 3.51, which fixes a security vulnerability issue.
Looks like Sony reacted to new homebrew hacks. In earlier security updates Sony at least also gave a game download as incentive to upgrade. This security upgrade has no incentive as of yet.
Via the Japanese Sony Playstation site.

The Sony PS3 firmware got updated yesterday to version 1.82.