I saw a stat during one of the games (or on PTI or Sportscenter or something) that said that the Spurs had the best winning percentage of any team in any league (NFL, NBA, NHL, MLB) since like the mid-nineties. So they've won 3 titles in 7 years, but played really well in every other year too. That definitely has to be factored into the "Are they a dynasty?" question.

That said, I don't personally think that's enough to call the Spurs a dynasty. But they could be on their way there, with all three top players signed through like 2010. They've also started picking up a bigger fanbase, especially with international fans and people that love watching Manu play. That can't hurt.