I just found this on Apple's Knowledge Base, apparently MobileMe will still show up as .Mac in Tiger:
http://support.apple.com/kb/HT1932
Hope that helps answer why Tiger won't be getting the update to change the .Mac Preference pane (but it will still sync to MobileME.)
EDIT: Ahh, meli beat me by "that much!"
SO will us Tiger users be able to sync our calendars and contacts with our work PCs without the use of an iPhone?