My thought is this:
Morning sleep between 3 and 6 am is usually mostly REM sleep. They spend more time in REM than adults do, and it usually looks pretty restless. If I had to watch my lo sleep through REM in the morning, I'm sure I'd be a nervous wreck!
I would let him sleep through it. If he cries out for you, go to him, but if you try to help him through it and he wakes regularly, that might turn into a habit that you don't want. By cry out I mean the cry escalates into a steady whaaaa sound, obviously awake with tears. Fussing is different than crying out.
Hope this gives you a bit of rest!
*HUGS*
Sonya =P