He's a switch hitter who can hit lefties, which means he can platoon with Pie.  

He's speedy and has nice OBP, which means he could bat 2nd when playing or even 1st when resting Soriano.  

He can play all three OF positions.  

He's blocked in Anaheim/LA by a half dozen other OFs, so he should be available.

The Angels won't want Murton (as in the Byrd trade), but a reliever may do the trick.  Wuertz for Willits?

Once the Orioles get done with any other moves they think they can make (which might even include dealing Mora or others), they would send Roberts to the Cubs for players to fill whatever holes they have left (probably pitching and Cedeno).  Then the Cubs could send DeRosa and a young, cheap pitcher or two to LA for Willits and perhaps someone with a bigger contract.  

Think about this fact, Ryan Theriot hit 25 points lower than Willits last year but had a higher slugging percentage.  Juan Pierre had a higher slugging percentage than Willits last year.  Willits does one thing at the plate, he walks.  So unless he is guaranteed to hit .290, he is basically useless.  He's also 27 this year so I'm not sure how much improve you could expect.  He's ok as a 4th OF but I wouldn't give up much for him.      

But realistically he's making minimum wage and those types of players are just not traded for packages involving relievers and de facto prospects so you should be able to tell there's nothing to this rumor without having any sort of inside scoop.

Roch Kubatko from the Baltimore Sun reports something funny on this:

From another report, though, they are speculating that if a deal happens, we won't know one way or the other for a couple of weeks.  Perhaps then, we can have some closure on this.

Source