Let's look at this from a fan's points point of view, a business point of view, and a personal (Sammy view)
To the fan (most of whom are sheep) they just roll with what the media tells them. In Sammy's early years, eclipsed by the '98 season, the media made Sammy out to be the second coming of Christ, he could do no wrong, and at that point a Sammy trade would have been suicidal.
Last Season Sammy walks out early on the last game, the media makes a big deal of it, Sammy acts like a bafoon, and the media spins it's wheels and what the fan gets...Sammy is bad, get rid of him.
Let's look at it from a Gibby-esque fan point of view who has an undying love for the game, forms their own opinion free of media persuasion (if that is possible) no one can take away from Sammy, The Cubs, MLB, fans,et al, what he has done for the game. All the years he put in were quality years in baseball form, entertainment form, and even at a personal level, he gave a lot of people someone to look up to. The years the cubs sucked, and he was there, he ran out to right field, smiling cheek to cheek, every game. That was awesome, inspiring, and motivating, not just to me, but to others as well. Basically, it is sad to see that kind of personality leave any organization, but this trade isn't when it left. It left when Sammy decided to leave the Clubhouse early, and hence the media took over.
What are the Cubs thinking? Obviously they are not getting what they are giving, sure there is an outside shot that Hairston stays healthty,and he has a breakout year as a Cub. Ask Todd Hundley how that works out. The Cubs were merely trying to save face with the PR Gods, so they don't have the public listening to guys like Mariotti brow beat them on a national level daily. As the media goes, so goes the public. The Cubs want to remain looking good, and not have the negative energy effecting their marketability.
As for Sammy. His actions speak for themselves. He wasn't happy anymore, and when you aren't happy, nothing good can come from it. He is still getting paid. He is still playing, and honestly good for him! I hope he is able to find a happy place in Baltimore, and return to his former smiling, knuckle kissing, running out to right field self!