I'll just add a couple more points here, from experience:
I have driven both RWD large American cars in deep winter conditions - throw some sand bags in the trunk, get some decent tires back there, and slip slide away down the road!
I've driven a 2WD pickup truck in winter conditions as well... mostly sideways, but that was half the fun. If the roads were that bad to travel on, I wouldn't go out, or I'd get a ride with someone else - but I would certainly be out there trying before giving up - even if that meant doing 270 degree turns through intersections on occassions! (oops)
I also had a newer BMW 5 series, RWD, manual transmission. It had traction control - and that system worked really well keeping the car from going too much sideways through a turn in bad weather. Unfortunately, the traction just wasn't always there - and I recall getting stuck on a slick road - the first car at a stop light, light turned green, and I couldn't move! Horns blew, people drove around me - and I felt really stupid.
Now I'm driving a Subaru WRX. AWD and performance. I get mid to upper 20's in the mpg rating - which is "low" for the size of the car, but not bad given the amount of power (260hp currently) the car has. But yeah, the awd adds weight, and uses more gas. A small tradeoff for having all weather performance. And Subarus aren't that much more expensive than their competitors, for what you are getting.
I've also owned some FWD cars in the past - ugh, they were annoying at times b/c of either torque steer (say as I'm trying to pass someone on the highways - I floor it, and hang on for dear life!), or poor handling (when the car loses traction in a turn, there's not much you can do with the gas, brakes, or steering wheel to gain control - just need to wait it out until you have traction again).
RWD vehicles handle the best out of awd and fwd in dry conditions - but that being said, just b/c a car is rwd doesn't make it better handling than a fwd car. Take a Crown Vic, and compare it to a Civic Si. I'd say the Civic handles better in dry conditions. Now, if the Civic were "easily" converted to RWD, and you compared that car to the FWD version of the Civic, then the RWD vehicle would handle better (turn faster lap times at the majority of race tracks out there) in dry weather.
Now, in wet conditions, we have to remember that we need to use more caution when driving. Losing control of either a fwd vehicle or a rwd vehicle means a loss of traction to the wheels you are controlling. In a FWD vehicle, all you are really controlling is 2 of the 4 wheels. The rear wheels just drag behind you - even the braking is done primarily by the front wheels. The end result is that if you lose traction to the front tires, there's little you can do in a fwd car. In a rwd car, if you lose traction to the front tires, you can manipulate the throttle (downshift, let off gas, give it more gas, etc) to regain control. If the rear gives out, then you can use the steering wheel to help regain control. If you're in a 4 wheel drift - it doesn't matter what kind of drive system you have, no input to the steering/gas/brakes is going to change anything until you regain traction.
So - the question is, what is right for Pontiac now? Who knows. Is going to all RWD platforms a good thing? I dunno. FWD certainly has it's advantages, especially with inexperienced drivers, or people who live in wintry conditions. Can Pontiac afford to lose a population of buyers in order to gain a "performance image"? Possibly. Will Pontiac ever be like it was in the past? No. Maybe that's a good thing, or maybe we just need to refocus on what the auto industry currently is, and what economic factors are at stake.
Personally, as a Pontiac fan, I wouldn't mind if Pontiac just built 3 different models - as long as those 3 cars were each ones that I would be proud to own. 4 cyl turbo FWD hatch, mid size rwd 2 and 4 door coupe/sedan with 6 cyl and optional 8 cyl, and a full size 4 door rwd sedan with an 8 cyl. That's pretty much all they need to succeed long term.
'68 Firebird, 350-4, 2 spd auto, triple black, Dlx Interior