The same as...
Or an aged Kid Marvelman? Young Marvelman?
Maybe Miracleman/Marvel Man will reappear in Dark Avengers #13?
According to Wikipedia.org:
Marvel Man's Powers: Abilities Superhuman strength, speed and stamina, flight, invulnerability, force fields, concussive energy blasts.
Sentry's Powers: Abilities Superhuman strength, speed, stamina, agility, reflexes, senses, and durability, light and radiation manipulation, Flight, Telepathy, Resurrection, Healing, Molecule Manipulation.