Agile is a hot word in software development and there are many articles written about Agile, or not so Agile, software development. Most articles focus on the methodology but Mark W. Schumann has written an interesting blog post that looks at what is required for success with Agile development. One of the interesting points is that Agile is really an attitude or a mindset. He explains this in the article here, found here.
Agile is a mindset not a methodology