You can generally save your Keynote presentation. I provided an answer on an error message on this thread:
http://discussions.apple.com/thread.jspa?messageID=10845696�
Here it is again, in case you can't find it.
Looking at the crash dump file it appears to be fonts and cache. You can verify by opening the file using another account on your computer (or another computer). If the file opens it may be the fonts. Here are the steps I used:
1. Open Fontbook - validate fonts then remove duplicates.
2. Delete the com.apple.iWork.Keynote.plist file in Home/Library/Preferences & related cache files (Home/Library/Caches).
3. Shut down
4. Boot up holding down the shift key (safe reboot)
5. Shut down again (Re-initializes the font cache)
6. Run Keynote
Peace