from: http://desktop.google.com/support/mac/bin/answer.py?answer=64429

Version 1.6.0.1552 (9/30/2008)

Feature improvements:
Google Updater is no longer required to install or uninstall Google Desktop.

Known issues:

Installation issues
During initial indexing, Google Desktop may have a noticeable impact on your computer, especially if your hard drive is highly fragmented or low on disk space. We've designed Google Desktop to be usable - if a bit sluggish - during this period. Once indexing is complete, your computer should return to its normal, speedy self. To expedite indexing, we recommend that you have at least 10 percent disk space remaining and defragment your hard disk before installing.
If you put the 'Double Click to install Google Desktop' file on a FileVault volume before running it, you may see an error message stating that you need insert a disk. To avoid this issue, don't move the file out of the DMG before running it.

Mail and browser issues
Indexing Gmail may take a long time because emails are downloaded in batches; each 'batch' is separated by two hours, and there's no progress meter.
If you use MailTags, you need to delete the existing MailTags Spotlight importer from /Library/Spotlight or ~/Library/Spotlight and reinstall version 2.0b9 or later. Earlier versions cause crashes during indexing.
Inability to search for MailTag tags in emails; the mail contents themselves can be searched normally. We are working with the MailTags author to resolve this.
If you have both Firefox 2 and Firefox 3 installed, you may see a message appear in the following instances:
The first time you launch Firefox 3 after updating to the latest version of Desktop, an 'Add-on' dialog will appear and the Desktop Search 1.1 extension will be installed.
If you launch Firefox 2 after having launched Firefox 3 and installing the Desktop Search 1.1 extension, you'll see an 'Incompatible Add-ons' dialog. If you see this message, click Don't Check. Despite this message, both Firefox 2 and Firefox 3 should work normally with Google Desktop.

Indexing issues
Desktop may slow down and appear unresponsive when completing an operation that involves a lot of files, such as installing Logic Studio. It will eventually catch up.

Other issues
We've received reports of some CVS (Concurrent Versioning System) updates failing with I/O errors. The workaround is to disable indexing during the update and re-enable after the update is complete.
If you're working with programs like CVS or SVN (Subversion), you may experience large amounts of file I/O. There's a known issue in Mac OS 10.4+ where large amounts of file I/O may cause a kernel panic. To resolve the issue, we recommend adding any CVS or SVN associated items to your Privacy list.