My airport never stops searching for networks, even when I'm already connected I switched to Lion soon after it came out on my MacBook Pro.  Now when I pull down the airport menu, it indicates that it is searching for networks all the time.  It does this even after I am connected to my preferred network.  I never noticed this with Leopard nor Snow Leopard.  Is this a bug?  a feature?  Should I care?
It's the refrigerator light problem.  It's searching because you pulled down the Airport menu.