a) Using Local Time means the internal system clock must be changed every time you move time zones or switch to a DST season.
b) Since other OS's overwhelmingly use UTC, dual booters will experience an odd "clock shift" every time they log in, making the clock many hours off in one OS anytime the time has been set in the other.
c) On the other hand, folks have stated valid concerns with switching to a pure UTC model: http://is.gd/D8RG
There was a registry hack to force Windows to shift to UTC time, but it's unstable.
Good would be testing that registry solution to get it working.
Better would be putting an option and a brief discussion of the pros/cons in the Change Date and Time menu. It needn't be too public facing, it could be in an "Advanced Time Controls" pane.