Matt’s written more build scripts than most and around 2000 we both made the mistake of thinking an XML based build file was the way to go. We also both now believe you need a full scripting language. With so much invested in ant, it will still be around for a while, but we think rake is the better solution for the future.
Maybe people are finally coming to their senses! I’ve been lobbying against using ant for quite a while now but with a lack of better alternatives it’s hard to drive the case. Now there’s both JRake that Martin mentions and Raven that I’ve written about before so it’s starting to look promising!