Boeing's main argument is that the procedure for dealing with runaway trim is completely unchanged compared to other planes, so this shouldn't require any additional training.
I understand their reasoning, but it seems odd to not even inform that there was a change, so that this would be more on top of the pilots minds. It's even worse that the system engages as soon as flaps are retracted. Since 737's usually take off with at least some minimum flaps, and retract them soon after take-off once enough airspeed has been attained (but while the plane is still at low altitude), this is quite dangerous. Pilot workload is high at this stage and there is limited altitude to recover.
That said, since this issue is on top of everyone's minds, and US carriers have added the optional safety indicators, we are unlikely to see a crash any time soon. Pilots will be jumping to the override switches at any sign of trouble.