Since we're on the subject, I wrote a patch so devices can be specified as hd(x,y), UUID, and also a label enclosed in quotes. Unlike what's currently committed, it works for renaming, hiding and selecting partitions as default.
It took quite a bit more work than I expected because I had to write code to handle XML entities, which I needed because they're the 'right way' to do things, but mainly because PList Editor uses them.
Some examples that I tested and should work now (based on trunk revision 264) follow. Quotes are mandatory with a single exception: they're optional in the new name to assign to a renamed partition.
<key>Rename Partition</key>
<string>"Windows" Windows 7; B8EA194F-69BE-35A4-AFF6-C51FCD0DA656 Mac OS X SL; hd(1,1) Hidden Partition</string>
<key>Hide Partition</key>
<string>hd(1,2) "Hidden Partition"</string>
<key>Default Partition</key>
<string>"Mac OS X SL"</string>
Any testers?