Hi David, I'll comment on the Explorer suggestion, as I added it:
I've also looked a bit at implementing support for IFileDialog, and the Explorer, but I have yet to dig too deep into either of them. Are there currently any known applications out there that uses IFileDialog explicitly? I've looked a bit, probably not enough, but I haven't been able to find anything except example code. Also, are there any applications that fail to run because explorer is missing functionality, or would the end-result of that suggested project function mainly as an end-user utility?
Off the top of my head I can't think of any applications that fail because it's missing. On the other hand, an Explorer app would make it easier to test other bugs in our shell implementation, e.g. missing support for the properties dialog (bug 8692.) --Juan