I might tolerate WotC using the spell format for simplicity, but they wont BE spells.The weave is only one interpretation of the interface.
Like I said.
If Psionics or Primal or Incarnium are spells, then wizards can add them to their books.
Then a cleric can dip into a level of psion and toss their 1st level psionic spell in a 9th level loss.
The new Fey/Shadow feats that let you know any 1st level spell of certain school. ANY SPELL FROM ANY CLASS of those schools.
Youll have to add rules to make the lore start looking screwy and weird.