Is it possible for my HTC Desire to interupt my iPod when I receive a call?
I've found something for you, although it may not treat your iPod the right way.  The only way to find out is for you to give it a shot.  Luckily the developer of this app offers a version that's a five day free trial.

Super BT Mono

If you're running stock Android 2.2 try this.
If you're running CyanogenMod try this.

I'd follow the dev's instructions on how to get this up and running, and just treat your iPod like the BT headset with which this app is meant to interface.  It doesn't say so on the app page in the Market, but on some forum thread (of which I've unfortunately lost track, dammit) someone mentioned that it will send notification tones and ringtones to the BT device.