Very cool to have more options on Mac emulation. I’d love to play shockwave 2 and super wing commander on pc.

Hi! And I'm looking forward to sound input in Mac emulators, eventually. Even if it's just low-quality "Mic-in" in mono.
So you could run iChat AV and do an audio or video conference (iChat works locally in a LAN via Bonjour)! ^^
Or use the Voice Password feature of Mac OS 9.x, so cool! - "My voice is my password" (anyone remembers Sneakers movie?)
Or you could use amateur radio software such as Cocoa Modem on Mac OS X Tiger..

Edit: Emulation of an USB webcam would be cool, too. Any type of webcam.
a) the classic USB 1.x type that needs proprietary drivers for Mac OS 9/X (such as Logitech QuickCam Pro 4000; iChat AV needs iChatUSBCam/iUSBCam helper tool)
b) the FireWire type (Fire-i, iBot Pro, ADS PYRO 1394, iSight etc)
c) the modern UVC type, USB 2.0 webcams of 2010 onwards (supported since Mac OS X 10.4.9)

Edited.

Edit: VBox 7.2.2 introduced "The virtual USB webcam" in the open source version.
Maybe that's useful to such emulation projects in general?
Link to Changelog