There is an update for Mac OS X to 10.5.2 which they claim can improve the stability and performance of current version of Mac OS X 10.5.1. together with security update.

Very significant change after the update, you can activated Time Machine menulet and use the shortcut function to browse preference or choosing other Time Machine devices.

Beside you can actually change the menu look and feel become translucent or just disable it by not checking it.