If you use the Maps function of your iPhone to any large extent, and you save a lot of location bookmarks, skip 2.2. I just updated to 2.2, and all of my saved map bookmarks have had the street address dropped. Every single one of them now only contains city, state and zip information.
I have been asked to clarify by a friend, who rightly noticed that when you search for a bookmarked location the 'pin' shows up in the correct place on the map. That is correct, the pins are located in the correct place; but the address information is not fully passed to the routing tool.
As you will see from the screen shots below, when you search for, and select, a previously stored location bookmark only the city, state and zip are populated into the location bar of the Directions application:
Reverting to an older version failed, and I am seriously annoyed.