How about either the ability to see the weather in two cities or to quickly switch between them? This would be useful for people like me going on a skiing trip and want to monitor the weather at that destination. Or perhaps you want to keep and eye on the weather near a family member that is out of state, etc.
I’ll vote for that. At the moment I have three cities defined (where I work, where I live and where my parents live), and, changing between them is a pain.
One more thing to go along with the multiple city idea: When multiple cities are selected, provide an option (maybe a check box for each) to select which (any or all) of them should have alerts. With the option proposed elsewhere in this forum (to update wallpaper when an alert is received), give the option to select which (any or all) should change the wallpaper).