Marshall - 5:40 pm on Feb 1, 2012 (gmt 0)
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More info [support.google.com]
Just an FYI - if your mobile version is on the same domain as your regular version, you may get warnings about duplicate titles or descriptions in WMT. However, I have not seen any warnings about duplicate content. Supposedly, using the mobile site map lets Google know it is not to be treated as duplicate content.