I managed to shoot myself in the foot this morning by doing the following:
No, (absolutely) NO.
If you say to Subversion it should revert a file, all changes are gone by the wind.
Only your memory can get them back.
Exception: New files you had added, will only lose their status "added", but the file will remain in this directory, only status is unknown("?")
Platform / Software exception: Using TortoiseSVN on Windows, Revert first throws the files into Recycle Bin and then reverts them. You can dig into the Recycle Bin to recover the files.