Can a commercial airliner be too heavy to take off?
It is possible to arrive at the runway with too much weight to takeoff, but this result is generally a mismanagement of fuel.  The most likely scenario this happens is when you are going to be at MGTOW for takeoff but need fuel to get to the runway (putting you over MGTOW at the gate) and are anticipating a long taxi or long lines at a de-ice pad. 

If the long taxi doesn't materialize this can result in getting to the runway with too much fuel.  Recognizing this, fixing it is often as simple as taxiing with both engines instead of just one.  If you are really overweight you just ask to get put somewhere you can wait while running both engines and wait for the weight to come down.  There is really no benefit to taxiing around the airport versus just waiting in one spot to burn fuel.