Assets for Mirkwood UI changes timeline?

[hawkeye666]

I realize that because of NDA it might not be possible for there to yet be an answer to this question but has there been any info yet on the asset and XML changes needed to make custom UIs Mirkwood compatible? Rumor has it that there are some new UI elements that may well render old UIs quite inadequate. Some one might be interested in working on updates before the official release, I suppose.