I'm tempted to try the replacement, especially if it will work with a bluetooth headset. I predict we'll see satchels and backpacks with a purpose-built port to let your corded headset out while your iPad is nestled in a custom sized pocket. There are already tons of backpacks with such a generic feature.

If Apple will tweak the notification feature so that you can let certain apps play a tone over the headset when you get a notice, then you can just pull out your iPad, see who called or IM'ed and call them the next time you have WiFi. If it's really important, just go ahead and call them back over 3G.