Apple has released Mac OS X 10.5.2 through Software Update. Of note is wireless connectivity, which has been a sore point for some users going back to 10.4.9 days. Airport Extreme problems, dropping connections to routers, etc.
Some of the updates of interest to mobile users:
– Improves connection reliability and stability
– Includes 802.1X improvements
– Adds support for more third-party routers, as detailed in this article
– Addresses an issue in which the backlight could turn off before Energy Saver’s backlight setting
There’s actually quite a bit more, which you can read at the link below.