I can live with psionics as spells, and even as psionics as a sorcerer subclass, but i really hope that they do it this way, they give the psion its own spell list rather than just defaulting to the sorcerer list. There's stuff there that just doesn't fit the psionic flavour, and that's much more of a concern to me than power sources, or even the interaction with dispel etc between psionics and non-psionic magic. Psionicists shouldn't, in my mind, be using Magic Missile, or Sleet Storm, or Fireball, or Creation, or Circle of Death, or Chill Touch, or Stinking Cloud, etc etc. And conversely, the sorcerer spell list misses out on some abilities that should be right up the psionicist's alley. Modify Memory, for example - surely if ANYONE can use that, a psionicist can? Dissonant Whispers, Awaken... there's lots of quintessentially psionic-type effects that are accessible to bards or even clerics, but that sorcerers don't get access to.
A specialist psion spell list that takes some of the big flashy evocations and necromancies off the sorcerer list in exchange for some of the bard's enchantments would make a huge difference towards making psionics feel like psionics rather than just a coat of paint over a bog-standard sorcerer, i reckon.