I'd like to see the "M" in the F=MA equation reduced. It would be nice to see the bike shed 60 lbs. or so. This is probably asking too much though for a mass-produced motorcycle this big and powerful...there's a price to be paid for an engine of this size. I also bought the bike because I wanted a sportbike with a reasonable seating position for someone taller than 5'10". So they better not shrink it down to litre bike size.
The gixxer 1k tail looks phenomenal on the 'busa, but I don't think it'd be comfortable for my wife.
Ultimately we're talking about Suzuki making changes that will compromise the appeal of the 'busa to varying subsets of the model's fans. It's easy to write a wish list, but more difficult to translate those wishes into reality without screwing up the wide appeal of the bike.
I'm certain one could shave the 60lbs. I requested off the bike with carbon fiber wheels, single sided exhaust (though it would have to keep the catalytic converter), and reducing mass elsewhere by using more exotic materials. Such an effort by Suzuki would drive the cost of the bike up high enough that many of us wouldn't be able to afford or justify owning the bike.
Overall, the busa provides a phenomenally versatile platform straight out of the crate. From that starting point, owners are able to customize the bike in the direction that fits their personality and riding style over how much time their budget allows. There's nothing anyone has mentioned in this thread so far that can't be accomplished individually through the aftermarket.
This thread could be titled "what mods have you done to your 'busa?" and it would probably have very similar responses.