Sony announced a new firmware update for the Sony PSP for today in Japan.

The Sony PSP 2.70 update has only a few improvements. The PSP browser supports now Macromedia Flash 6. The PSP RSS feature can now deal with audio resources (e.g.: podcasts) and you can also download files directly to memory stick from the RSS feed.

To motivate you to upgrade your Sony PSP firmware Sony launches the first Trial Game download for the PSP. The LocoRoco game demo requires firmware 2.70. The LocoRoco demo will be available on this page (Japanese). See my first impressions of the LocoRoco Game.
More details about the Sony PSP Firmware 2.70 in this Sony announcement (Japanese). Download for Japanese Sony PSP consoles is available here (Japanese).

See also the Sony PSP Firmware 2.60 and the rumors about Firmware 3.0.