Yep i agree-  the networking option has awesome potential.

Imagine a head to head game with your mate across the other side of the world with his game being displayed on the LCD - or at least his targets he has hit/challenges he has completed.

Then bring in a mode where once he makes the shot, a drop target pops up to block that exact shot on your machine, therefore twice as hard for you to complete, then you have to quickly try and nail other shots so his drops pop up to block certain shots.

Then for the final or multiball, as he gets shots, add balls and/or subtract balls from your machine

Or weaken flipper power for a period so you can't make long shots

Or even just have some mildly abusive taunts/sound effects when you are getting beaten.

Should be dead simple and cheap to implement, just standard bits (wi-fi card, drop tagets, coils) with some programming required