I'm not sure this has been mentioned, but David Buck wrote a nice essay about why he switched from C++ to Smalltalk for the UI part of ElastoLab. He also describes how he uses an update downloading mechanism like Squeak's to get bug fixes to his users. See:
http://www.whysmalltalk.com/smalltalkcomparisons/elastolab.htm
Incidentally, the program is only US $20, which is very reasonable. If I had a PC, I'd buy a copy. He also offers a free 7-day evaluation of the full program using a rather clever server-based scheme to revoke the privelege after the seven days expire.
I'd love to see David succeed. It would encourage more of us to build and sell cool and interesting software written in Smalltalk.
-- John