Summaries from all the major articles not mentioned.
IGN US
"As for the feel of the vehicles, I'd put the game somewhere around the level of PGR in terms of realism, though it's admittedly been a while since I've played PGR so that might not be a perfect match. Regardless, it's certainly a far more realistic experience than pretty much any previous game in the franchise, and for my money, more fun to drive as well. To be sure, while it's not as demanding as Gran Turismo, you'll still need a fine touch on the accelerator, knowledge of whatever track you're on and, most of all, a large amount of respect for whatever vehicle you're in."
Gamespot
"Shift is all about your experience as a race driver. The action will take place on existing, licensed racetracks, on new racetracks created for Shift, and on street circuits. There is no open-road racing this time around, and we were promised you won't be pursued by the police or have to take part in old-fashioned street races. Instead, Shift will feature 15 real-world locations in addition to fictitious tracks. The game will feature more than 70 different cars in total, including hatches, classics, and exotic imports. Though we didn't get to experience Shift's multiplayer, the game will support 16 players in online races. Need for Speed: Shift combines impressive real-world locations and cars, solid simulation gameplay, and some interesting additions to help immerse you in the racing experience. It's currently set for an autumn 2009 release on the PC, Xbox 360, PlayStation 3, and PSP."
In my opinion this looks to confirm an almost exact clone of GRiD. Some articles say its like a sim but IGN clearly states that the cars drive like in PGR and not Gran Turismo. So in other words it is not a sim and only looks and feels like a sim which is exactly what GRiD was. Unless this game has realistic driving physics it will be a pass for me (as a fan of GT and sims in general). To think I actually got excited. Well when I rent it I hope I am proven wrong.
Update:
Found some promising opinions from nfsunlimited.net
"The realism doesn't end in the cockpit though: as soon as the race starts you notice that at full gas, your tires will start spinning and the car will not move like you're used to in an NFS game. The physics engine is completely new and never before seen in an NFS game. They say it's about as realistic as the one in Forza 2 or Gran Turismo and I have to agree. Having tried several different cars (Lotus Elise, Audi RS4, Chevrolet Corvette Z06, Porsche 911 GT2 and Pagani Zonda) I can say that each car handles very differently and mastering a powerful car like the Zonda will take a lot of effort and preferrably an analogue controller. Flooring the acceleration at low speeds in turns with a Zonda will end in spinning out and with bad luck hitting a wall. And crashing is not a good idea - your car will get damaged and your vision will be blurred for a while - like hitting your head hard into a wall. But once you get used to the car and start messing with the assists (turn off ABS and traction control to go hardcore, or turn on the driving line to go a bit casual), all the frustration will be gone and you'll start enjoying the demanding but genuine driving engine, the great sense of speed and the incredible detail in everything - the cockpit, the world and the AI controlled cars (or your car if you use the chase camera). Now if you are getting worried that this is not the Need for Speed you are used to, you'd be correct; it's not. It is completely different, but the core features are still here: great sense of speed and a large selection of top cars.