Related to this answer wherein it is demonstrated that "the ability to manifest psionic powers is a psi-like ability".
Also from the SRD, which seems to establish that Psi-like equals Spell-like:
Psi-Like Abilities And Feats Creatures with access to psi-like abilities can use the feats Empower Spell-Like Ability and Quicken Spell-Like Ability.
These feats can be used only on psi-like abilities that do not have increased effects due to augmentation. Furthermore, the creature can empower only a psi-like ability with a level less than or equal to half its manifester level (round down) minus 2, and can quicken only a psi-like ability with a level less than or equal to half its manifester level (round down) minus 4.
Creatures With “Psionics” Entries Psionic monsters often possess spell-like abilities that are identified as “psionics,” instead of “spell-like abilities.” For all intents and purposes, creatures with spell-like abilities described as psionics are considered to possess psi-like abilities, and they manifest their powers as described above.
And finally, from Savage Species:
You convert a spell-like ability to a supernatural ability.
Prerequisite: Innate spell-like ability.
Benefit: One of your innate spell-like abilities becomes a supernatural ability. It is no longer subject to spell resistance, though it can still be suppressed in an antimagic field. Using this ability does not provoke an attack of opportunity. The number of uses, if limited, does not change. The effective caster level equals your total Hit Dice or the effective caster level of the original ability, whichever is higher.
Special: You can gain this feat multiple times. Its effects do not stack. Each time you take it, it applies to a new spell-like ability
Thus, the question: what rules effects, if any, would converting the ability of manifesting psionic powers itself to a supernatural ability have?