I'm happy for both teams. I am also happy to see the resurgence these past few years of smaller market franchises like the Royals and Orioles.
As a life long Red Sox fan I have to be rooting for the Cubs. Its a different experience: Cubs fans have put up mostly with lots of truly bad teams and the occasional heartbreak with good teams. For Red Sox fans, especially my generation (I was conceived during the Red Sox "Impossible Dream" 1967 pennant run and am the youngest sibling by 6 years, can't help but believe its related to my parents celebrating a big win, so thanks Yaz!), its been about the close calls and heartbreaks. The Sox have only had maybe 6 or 7 losing seasons in those 48 years.
The downside to winning in 2004 is that you go from a long suffering fan of a heartbreaking team to another A-hole rooting for a big payroll franchise overnight.