How safe is my 2009 Toyota Corolla now that a shim has been installed, supposedly the fix for the sticking accelerator?
Nobody knows for sure at this time. But countless people are looking onto it.
Meanwhile, be sure you know where neutral is on your tranny. Should the car accelerate uncontrollably, immediately put the tranny in neutral, pull over to a safe place, and then turn the engine off. Don’t worry about the engin ervving, the ECU will protect it.
Nobody–including the Toyota folks–can say for sure.
When the president of Toyota Motor Sales USA was interrogated by a Congressional Committee, he stated that he “could not guarantee” that the current recall(s) would resolve the unintended acceleration issues.
You should practice the recommended procedure to follow when the accelerator is “stuck”:
Press the brake pedal VERY firmly in order to exert maximum pressure on the brakes
Shift to Neutral
When it is safe to do so, steer the car to the shoulder of the road
As soon as the car has stopped, throw the transmission into Park and set the e-brake
Shut off the engine
Call for a tow to the Toyota dealership
The odds are good that you will not have a problem, but it pays to be well prepared, just in case.
If you’re really worried, get rid of the vehicle.
Who knows, maybe we’ll see a “Cash for Toyotas” plan. Trade your Toyota in for a new vehicle from any other car maker and get xxxx amount of money for it. 
edit: While it may be prudent to know what VDC said, what should one do if they’re stuck in the middle of rush hour traffic? Not everyone travels the freeways all the time.
No one really knows. Frankly I would not hesitate to drive any Toyota.
They certainly appear to have some problems, likely more than most other cars, but the worse car they have sold in the last 10 years is going to be safer than the best car sold 40 years ago when they were the same age.
All makes have had reports of this kind of problem. They are generally rare, but with millions of Toyotas sold and so many people worried about the problem, they are going to get lots of reports. Some I fear are people who are looking for some sort of money or a new car when they have not really had any problems.
This is not to say there is not a problem, but don’t over worry about it. Do take some time to think and practice (while parked) the procedure of getting into neutral and pulling off to the side of the road.
I have to add one thing. I would feel much safer with with a Toyota behind me than any other car with the driver texting, or trying to finish off that coffee while they are driving. I wish more drivers would worry about themselves as much as their car.
Thank you all for responding and your recommendations. You have put me a little more at ease. I actually have not had any problem with the car accelerating and have been driving it for a year.
Do recall that unintended acceleration or not the single biggest factor in the safety of a car is its driver.
The accelerator pedal wear that leads to sticking only occurs after it is worn enough. Your car was and is safe to drive. The pedal was altered to ensure that you would never face unintended acceleration. If it turns out that there are other issues that lead to unintended acceleration, it will be discovered due to the high profile of the issue. But even if it is true, very few cars seem to have experienced it. There are millions of Toyotas on the road, and far fewer than 1000 seem to have been affected - way less than 1%.
Also, someone on another board found an old article discussing sticky throttles - in 1960, IIRC.
We are told: "Simply put the car into neutral then turn the engine off."
NOT! Check out these video clips:
TESTIMONY OF TOYOTA DRIVER WHO ‘LOST ALL CONTROL’
(where putting car in neutral and unable to turn off engine!!!)
http://news.bbc.co.uk/2/hi/business/8533129.stm
and
"IS TOYOTA’S SOFTWARE TO BLAME FOR SAFETY PROBLEMS"
http://news.bbc.co.uk/2/hi/science/nature/8535477.stm