Make sure he re-torques the stem spanner nuts (that means resetting the bearing-setting spanner, then the locking spanner, then of course 85 pounds of torque on the top cap nut that is visible above the tree clamp.)
Also make sure that the bolts have been properly installed (visual and feel) on the clamp where it attaches on the fork legs. There have been a couple of instances where folks drove away and later found these bolts to be loose.
Finally, make sure that your handle bars are back in the same position as they were before the work. I found that after my switch install, the right side was mounted further forward than the left side. It was just a simple oversight by the mechanic, but he fixed it in just a couple of minutes while I waited.
Then, if you fully trust Yamaha and their ability to fix this switch once and for all, you are done. Otherwise, order the Brodie switch contact bypass harness, install it, and go forward with life.
Most of the stuff I have mentioned above can be found in the bin of facts (torques for the spanners) if you would like to see a great collection of factoids about your bike.