(Rob’s note: Apologies to Colin, he put this up here in draft form weeks ago and even though I promised to flip it to live two weeks back, I forgot. So Colin… a thousand pardons. This is awesome!)
From Colin:
For those of you that use DAX.xml with Notepad++, there is an update available at https://powerpivotfaq.com/PowerPivot%20Samples/Forms/AllItems.aspx. There is also an update of the DAX functions file. Although I created the new files shortly after downloading the Denali version of PowerPivot, I held off making the files available because, at the time, I didn’t know whether any additional functions would be added in the final release. I have it on good authority that no additional functionality will be added on top of CTP3, so it’s unlikely that the files will change between now and PowerPivot V2 RTM. Note that the list of functions contains those that are not currently documented, including the very important KEEPFILTERS function, which you can read about in this superb post from Alberto Ferrari. Perhaps this function should have been called KEEPUSERSIGNORANT (okay, just kidding 
).
If you missed the Notepad++ post, and might be interested in using this excellent tool to author your DAX measures, you can read the original post here.
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