Mac Magazine XML code (http://translate.google.com/translate?u=http://macmagazine.com.br/2011/06/28/arquivos-internos-do-final-cut-pro-x-comprovam-que-apple-esta-trabalhando-em-suporte-a-xml/&hl=en&langpair=auto|en)

This is a good sign because it means the feature was already anticipated but wasn't ready for v1.0.

Or, as the article states, it could also mean that Apple considered XML early on, but decided against implementing it. Could go either way.

Based on quotes from various Apple spokespeople this past week it sounds like more and more "pro" features will find their way back into FCP X, and at a much faster cycle now that everything is downloadable.