As long as the audio/video equipment has compatible outputs then the Slingbox will be able to rebroadcast the signals into a multimedia stream.
The only compatibilty issues you'd have to worry about is whether or not you can control the device remotely. Remote control of the device is handled by the IR Blasters of the Slingbox, but you'll need the proper IR Codes to control the respective device. There isn't a list that's laid out for us, however there's a widget that you can query on this web page (http://support.slingbox.com/get/KB-5000164).
For devices which aren't offically supported, Alan Richey is able to create remote update bins for most devices which are listed in the Logitech Harmony Database (http://www.logitech.com/harmony/components).