I agree completely with all you who say that the Wee is a great package as it is in stock form. Some of us just can't leave anything alone, and mod just for the fun of seeing what can be done. Does it make sense from a dollars per horsepower standpoint? No. Not really.
When I started modding my 07, I specifically addressed everything I didn't like about the bike: Harsh front suspension that dives too much when braking, poor feel from the front brakes and not quite enough stopping power, the moped-like sound and ugly mechanical noises from the motor (in my case- cam chain tensioners. You should hear it with the manual tensioners!), and a lack of top end when passing at high speed. Your list could be different. We all want something different out of our bikes.
For me, the reason to do this was to perfect what I have found to be the most enjoyable all-around bike I've ever owned. What's a couple grand to right what I feel is wrong, when you look at the cost of a new bike and consider that you might end up with a great machine with another list of things you don't like? I've never yet owned a bike that is perfect in every way.
On the 2012, the cam swap might not be really beneficial, because Suzuki has already upped the horsepower. I could be wrong, but I suspect they have already changed the cam profile in the new models. Maybe somebody could confirm that. For my 07, it made a really nice improvement, and that "loses low end power" nonsense is really just that. It's at least as potent everywhere in the rev range, but noticeably better on top, which is perfect, in my opinion. That's the only place I really found it lacking. These twins sound sweet with a free-flowing exhaust. I'm loving the Akrapovic without the baffle installed. It will be too loud like that for some, but for me it hits all the right notes, and is nowhere near as loud as the American V-twins I see on the road everywhere.