Apple released two separate software updates yesterday. The MacBook Battery Update 1.4
"improves the ability of MacBook batteries to maintain a charge when the system is shut down and not used for an extended period of time" and is for 13" MacBooks
In addition, the Digital Camera RAW Compatibility Update 2.5
adds RAW support for the Nikon D3X and Epson R-D1x in iPhoto '08 & '09 as well as Aperture 2.
The battery update
and the RAW update
are both free downloads from Apple.