Thanks for all the votes and comments for this suggestion. We are considering improvements to how Excel deals with reformatting (or not) as data is imported and entered from CSV and other sources. Your comments are very helpful.
Steve K [MS Excel]
An error occurred while saving the commentMBT commented
Yeah, I can't believe that this was removed. Oddly though, its still possible to open files with arbitrary extensions using VBA. I have written a script to handle it for now.