The great thing about early commutes is less traffic! I leave my house at 4:45 am. It's amazing how easy it is to get around. I live in a somewhat urban area and at that time of day, it's often I won't see a single living soul on the roads. All of the party-ers and criminals have gone to bed, but the worker-bee's aren't yet awake. it's just me and the road.
One thing that has made a difference for me (mentally) is to have great lights. After cruising around in thee dark for a while with $20 lights, I decided it was time to step it up. I have a headlight that I splurged $170 for and taillights worth a combined $90. It was hard to spend that much on lights (nearly half the value of my bike) but it really is piece of mind. When I ride at night, I can see my light lighting up reflective road signs over a mile away and the area immediately around me is lit up like daylight! I would probably be ok with less (since there are no humans around), but it's piece of mind and makes the night "less night".
Dont get me wrong, I would love to wake up at 8am every morning to a lazy breakfast and the newspaper, but my career demands early hours. On the rare occasions I do go in late (8am or so), I curse myself for doing it as I'm battling millions of cars.