I upgraded one of my Zunes to the latest 3.0 software and was very pleased to read the latest news that manual sync capability is now a part of the Zune desktop software. In the past I had issues connecting my Zune to my home and work PC and losing content. You can now manually control your content and if you connect your Zune to a PC with limited hard disk space (a new netbook, perhaps?) this could actually be quite beneficial. You may now delete large movie files from your PC after getting it onto the Zune and then delete it from the PC drive while it remains on the Zune.
With manual sync mode, you control syncing and deleting of music, videos, and pictures. Podcasts, Friends, and Channels do not have a manual mode option and these remain in automatic sync mode because of the nature of their content. I appreciate the new capability and also am very pleased that I can still upgrade my old original Zune 30 to the latest firmware.