Teams that are in the playoffs can't be taken lightly but as far as the series between the Nuggets and Spurs is concern i think the Spurs has a good chance of winning that and if they play the Blazers which also has a good chance of winning their series against OKC, we can base on speculation on history on their head to head at the elimination which is even. Blazer vs Spurs in the second round would be a good series but it's not over yet on the first round.
Nuggets is on different level this year, so if ever the Spurs win this series, Nuggets will surely give them a hard time. In fact, my intuition is telling me that this series will lead to game 7. Tough match up btw.