I don't think it's a long season that's a factor (although it is) but the this is a matchup that has little appeal to much of the country. Yes, you do need those big market and well known teams (Yankees, Red Sox, Dodgers, etc.).
Let's look at the WS since 1999 and see which probably had interest (totally unscientific and biased :wink2
:
2000 Yankees v. Mets - I went to a WS series game at Shea so you know the answer. However, you had the Yankees so that drew interest.
2001 - Yankees v. Diamondbacks - Yankees were the draw
2002 - Giants v. Angels - probably not as well rated but we probably tuned in to see Bonds.
2003 - Yankees v. Marlins - Yankees again
2004 - Red Sox v. Cards - Need I say more
2005 - White Sox v. Houston - A dud. Thank god it was over in 4.
2006 - Cardinals v. Tigers - Think this one captured a little more imagination because of the Cards but not a big draw.
2007 - Red Sox v. Rockies - Red Sox again, plus Rockies in it first time.
2008 - Phillies v. Rays - Not a Yankee like draw but some interest.
2009 - Yankees v. Phillies - Yankees
2010 - Giants v. Texas - I found it exciting but didn't draw
2011 will probably verge on 2005; I certainly have no interest and will probably not watch too much or at all. No rooting interest and no fizz there, except in Missouri and Texas and national followers of these teams.