Supposedly the Office 2007 formats are really compressed ZIP files, which contain directory structure with semi-proprietary XML content and and embedded media your document may use.
(Some more info: http://msdn2.microsoft.com/en-us/library/ms406049.aspx )
Have you tried opening the file with winzip?
Anyway, tip for the future: If you have any doubt that your content may not have been saved, you may want to:
1) copy all your content to the clipboard
2) open another copy of your application
3) paste your content
4) try saving again under a different name
Or, worst case, if you do have to close your app altogether first, at least you still have your text on the clipboard, just in case...
(Some more info: http://msdn2.microsoft.com/en-us/library/ms406049.aspx )
Have you tried opening the file with winzip?
Anyway, tip for the future: If you have any doubt that your content may not have been saved, you may want to:
1) copy all your content to the clipboard
2) open another copy of your application
3) paste your content
4) try saving again under a different name
Or, worst case, if you do have to close your app altogether first, at least you still have your text on the clipboard, just in case...