I could move to Alaska and I would still be a Yankees fan, I would watch local teams but my main rooting interest would be the Yankees. Same with football, I will be a Giants fan and would always root again the Cowboys no matter who they play.
Being a longtime 49ers fan, I certainly won't forget '92 and '93, so I probably would not be a Dallas fan unless I somehow ended up in or near Dallas.
I used to hate Dallas back when I was in the time wasting habit of hating teams. As much as I hated Dallas, and the Niners inability to contain Smith, I was totally in awe of his ability to run with the ball. Nobody, except for maybe Sanders, had the grace of Smith during his Cowboys days. It was all worth the heartache though since the Niners came back in '94, stopped the Cowboys from a possible three-peat, and gave poor old Steve Young a ring. That was the Niner's greatest moment outside of the '81 season with Joe Montana and the Niner's first SB championship.
As much as I didn't like the Cowboys being called "America's Team" and compared to the Yankees (baseball's America's Team), the Cowboys had a great 20 year run, great years in the '90s, and some good performances more recently. They had the best lineup of names with Landry, Dorsett, Smith, Staubach, Aikman, Jimmy Johnson, et. al. along with 8 Super Bowl appearances, 5 wins, and an obscene number of division titles. And when they won, it wasn't by just getting by, or by any luck since Dallas more often than not destroyed their competition. They built a legacy, or mythology, or a combination of both, which is totally unmatched in that sport. Their uniform colors are extremely popular among non-football fans. And their cheerleaders don't hurt their visibility either.
The Niners, with Montana and Young, got close to the Dallas legacy racking up 5 Super Bowls, 19 seasons in a row with pretty good chances and/or a deep lineup worthy of the big show, almost as many division titles as the Cowboys, and their own list of great names. But they still came up short and were not, historically through the sport, the same as Dallas.
To break all the team records Dallas holds, it would take someone like the Niners or Steelers winning a couple more SBs, hiring a Landry type of coach, and tie on another ten division titles and hall of famers.
Since the early to mid '60s, the Cowboys, love or hate them, have been on average the most reliable team in football. As much as I hate to say it, I think Romo and company can make it to at least an NFC crown a couple of times before they get too old. And God forbid, a 6th ring with 9 overall SB appearances.
But America's baseball team, the Yankees, are probably not going to face a hard World Series if things go according to how we have seen them perform. Unlike the Cowboys, who seem to have fans everywhere who will root for them no matter what, I think many people on the fence who could turn into Yankees fans, won't find an easy time rooting for a team that just picked up their 40th American League pennant. This may be a chance for new fans or people with no really strong preference, to fall in love with the Phillies.
Any curse that the Phillies had of being an original, old school team that has not performed up to expectations over the decades compared to other old teams (Phillies were the last old school team to win 1 WS and last to win 2 WS), can put every criticism to rest by adding a back to back to their list of achievements while also taking out a talented Yankees roster. This is what I think Philly needs to do to get respect with the likes of the Cardinals, Red Sox, Reds, and Dodgers as a solid team people could point to as a postseason team.