After issues were reported with the PlayStation 3's 2.40 firmware update, it appears the update has been completely pulled from the Network. This blogger had not updated yet and, when attempting to, was told the latest version was already installed. A tipster reported the same thing. We've contacted Sony for comment and will update as soon as we hear back. If you haven't updated yet, give it a shot and let us know if you're successful.
[Update: Sony just updated the PlayStation blog stating that it has "temporarily taken Firmware v2.40 offline" due to "a limited number of calls from consumers experiencing an issue with installing the system software update on their PS3."]