It's the economy, stupid.
You can't take voting patterns out of their proper context. The economy, or perception of it at least was grim and many felt Bush was doing nothing about it.
Yes, but ever since then they haven't been in the Republican column either.
Really, really depends on the location of said suburb.
I agree with all of the above. Today rural areas and exurbs outside the Northeast are the GOP's stronghold. Most suburbs are increasingly ethnically diverse (not to mention more diverse i terms of lifestyle and social attitudes) and suffering from infrastructure decay, just as older cities are or were.