The glass panel instruments still use the pitot/static system. If your
static port becomes plugged, pull the alternate static source knob. Don't go
breaking any glass instruments.

The glass panel does not use gyros, but the backup instruments do. The
Garmin 1000 gets pitch information by detecting changes in the vertical
component of the Earth's magnetic field and by cross referencing that with
information from the GPS. It does the same with roll information. It sounds
complicated, but it really is just a fancy compass.

If it were not for legacy aircraft in the ATC system we could dump the
excessively complicated dependence on magnetic headings and give all
vectors, winds, headings, etc., relative to true north. Continually mapping
the shifting magnetic field and updating databases, IFR and VFR charts,
radio navigation aids, and training materials is a major expense.