  In this comment it is pointed out that the electron velocity of the same
order as observed in graphene had been measured in GaAs submicron devices long
ago. Particle- antiparticle asymmetry related with electron and hole effective
masses in graphene seems puzzling as hole in a condensed matter system cannot
be treated as anti-electron. It is argued that there should be a universal
electrodynamics for QHE and superconductivity. In this context attention is
drawn to the new approach based on massless electron and the interpretation
that magnetic field represents angular momentum of the photon fluid.
Measurement of electron velocity in graphene and GaAs in parallel is suggested
for testing the massless electrodynamics.
