Miscellaneous Psionic Creatures, named after... one fairly unremarkable nerve in the human body?
Anyway, the phrenic template is a rare example of WotC actually judging a LA well. Its current rating of +2 is widely accepted as fairly balanced, and while it's by no means a top-tier pick it is still something a fair number of characters can benefit from.
The benefits are simple but elegant: power resistance, some bonuses to mental stats, a free power point, and a long list of HD-based PLAs, in a similar fashion to Half-Celestial and Half-Fiend. The powers are pretty useful, including save-or-loses, solid utility, and buffs.
The current rating of +2 is more than reasonable, and will not be changed.