Sony releases firmware 1.90 for the Sony PS3. The information on what is new in 1.90 appears Japanese news site Watch Impress before it hits the usual pages on the Japanese Playstation site.

The new Sony PS3 firmware 1.90 features several improvements. For instance you can select a XMB desktop background, rearrange games stored on your PS3 hard drive, music CD frequencies support now 44.1, 88.2 and 176.4kHz, 1080p 24Hz Blu-ray output can be forced, AVCHD support for stored video and added browser security.
The Firmware 1.90 features lots of neat little improvements, but no major new things.
The new Sony PS3 firmware update 1.90 will be published tomorrow on July 24th. The Sony PSP firmware 3.52 will also be available tomorrow. It features improved support for Playstation Network games.

Update 07/24/07:
Sony PS3 firmware 1.90 and PSP firmware 3.52 available now

Via Watch Impress (Japanese).