I think MLS is improving as well, not only with the play on the field, but also with the fact that many teams are playing in soccer specific stadiums, as opposed to playing in cavernous football stadiums.
For example, Red Bull New York just moved from Giants Stadium to Red Bull Arena this year. Picture here:
http://en.wikipedia.org/wiki/File:Re...or11062009.jpg
This should improve the atmosphere of the games IMO. I'm hoping to catch an FC Dallas game sometime soon as my folks live in Dallas.