There are also new keys in the Registry:
Although there's no information about the new service, it seems that Google wants to create a centralized update system, similar to Windows Updates, that will be installed with each Google software.
Google Updater is also a program that installs and updates the software for Google Pack, but this one has a GUI.
* Picasa 2.6, Build 35.83 (beta)
- changelog: mostly an update for Vista
- download here