I also vote yes to this, Blizzard even though they have Esports and all that ready and prepared with the launch of SC2 and needed observers, it can still be quiet entertaining, especially to someone who's just in the right mood to play dragon commander, or so, but not quiet engage. Half the time thats myself. :P
(when) videos go on youtube, people would like to see skirmishes and such, other than the campaign, observer mode would be quiet useful at points for that too.