Cold Hard Football Facts seems to think so. They looked at all teams who improved their win total by at least 5 games, and then checked how they did the year after their improvement. Turns out that most teams that did so, failed to improve again. This should hardly be a surprise, though, as the NFL is a volatile game, and any team that gets to 10 or more wins is unlikely to repeat that anyway.
Now, I did point out earlier that the Bucs have a number of hurdles to overcome to win next season. It's true, and Cold Hard Football Facts makes a number of the same points: simple regression to the mean suggests it's unlikely the Bucs will repeat and the schedule will be more difficult. But there's one thing they're missing: the Bucs have Josh Freeman.
Of all the teams listed by Cold Hard Football Facts only a few teams had a good, young, healthy franchise quarterback on the roster. The 2009 San Diego Chargers were one, but they were sank in 2010 by their historically inept special teams play. They really put the 'special' into special teams, and that shouldn't be a problem for the Bucs. The 2006 New Orleans Saints had Drew Brees, but the talent level around him at the time was minimal at best. The 2008 Atlanta Falcons are an interesting case, as they share a lot of similarities with the 2010 Buccaneers. Still, they only declined by two games. The Green Bay Packers would be a good example, if their 'decline' had not ended with a Super Bowl title. The same goes for the 2003 New England Patriots.
This team will go as far as Josh Freeman takes it, and Freeman can take it very far. The fact that in past seasons large upswings in win totals aren't often followed by another season of increased wins isn't all that meaningful, as few of those teams were in the position the Tampa Bay Buccaneers are in now. While the Bucs have some question marks on the roster and problems to solve, they have the tools to do so and win in 2011.