OOXML is text based now. So Office 2007 should be text capable. Sharepoint is generally horrible with that I agree, but I think it uses the default MS word mechanism to do that which stores changes with the file at the end.... kind-of a bad idea.
Also fun fact: Sharepoint agreeably sucks more than any other MS product but it's not actually written by MS, but a large part of it is written/owned/supported by Akamai Technologies
OOXML is typically stored as a compressed ZIP archive. Even when its decompressed to its constituent XML files, modifications are performed without much regard to how a diff will look.
This applies to auto-generated XML in general -- ODT is not immune. LaTeX and reStructuredText are the only formats I know of which are suitable for professional publication and can be usefully diffed.
Most diffs do that. The Diff that ships with gvim on Windows has this option on by default and I couldn't find where to turn it off because it was severely screwing up what I was diffing.
Very weird support call. I finally said listen I think it's a problem with Sharepoint, and they forwarded me to Akamai, however they answered the phone as MS, but the CallerID showed Akamai Technologies.
If you've ever dealed with MS Business Support they have sections for every single product and some products are segmented by parts.
Oh. MS's SharePoint premier support is definitely staffed with contractors; the two times I called, I talked to non-employees. I wouldn't draw any conclusions about the development staff from that though.
Also fun fact: Sharepoint agreeably sucks more than any other MS product but it's not actually written by MS, but a large part of it is written/owned/supported by Akamai Technologies