FWIW:
1. The 2.5 engine in the new Rabbit and Jetta isn't that bad. It has nice low end torque which is nice when you consider when you'll be using it most, such as getting on the freeway on ramp. I'd personally perfer low end grunt over a high-revving motor, but that's just a personal pref. Also, while estimated EPA milage is nice, it all depends on how you're driving the car. I could be driving a Fit, but if I leadfoot it all the time, my milage is going to suffer.
2. I wouldn't be so quick to charge the new Mk.V Rabbits and Jettas with the same reliability problems as the Mk.IV models. It's a completely different platform.
3. The diesel model of both the Rabbit and the Jetta should be coming back to the states soon. It's dependent on the upcoming diesel restrictions and implementation of ultra low sulfur diesel. Those models easily get well north of 40ish MPG.