I might be a little late, but I decided to take a look at the file.
All Mathematica notebooks are actually stored in a (semi) human-readable symbolic form, represented by a nested set of Cell objects. When one knows where the error is, one can manually repair a corrupted notebook.
Mathematica reported the error as being in the last cell group. I wasn't able to find its exact origin, so I had to delete the group.
Then an error was reported in some form of cache information at the bottom of the file, stored in comments. My guess is that it has something to do with undo history or clipboard storage. I deleted that as well, as it shouldn't be essential to the operation of the notebook.
That was enough to get the notebook open, but at the bottom of your content there was an oddly large large string of text starting with a U, probably a remnant of the corruption.
Below that there was a set of text cells containing the actual raw contents of the file. I have absolutely no idea why Mathematica loaded the file in this way, but I deleted them.
Finally, the file was rid of corruption. Hopefully it's still useful!
Slightly relates as it has to do with keeping backups of your work, and there have been several discussion recently about corruption and backups, take a look at this tool that I recently posted on:
The link: http://support.wolfram.com/kb/3300 appears to be out of date as there is no *RestoreNotebookATfunction in AuthorTools in Mathematica 10. There is a RestoreNotebook function.
It appears my notebook and backup of my notebook on a separate drive are too far gone to benefit from the code for RecreateNotebook above.