this is the only pic I've ever found of the front panel hooked up:
as you can see, the 4-pin power connector, and an IDE interface (which connects to the AUD_EXT connector on the X-Fi), but no connection that appears to interface with the proprietary connector on the X-Fi . . .
Funny thing is - the Audigy series also had a 5.25" bay Front Panel, also (I've seen ones with the Audigy logo and the Audigy 2 ZS logo):
notice how EXACTLY THE SAME
it is to the X-Fi FP . . . and the Audigy's stouted the same AUD_EXT connection (albeit different sources for the pins), and also the 10-pin proprietary connection . . . although, I have yet to see anything that actually makes use of that 10-pin