Quite frankly, I'm shocked at the bitter recriminations and outraged surprise registered here. It has been apparent for quite a while that the mystic is dead. Anyone who has been keeping up with Unearthed Arcana for the past year should not be the least bit surprised by this route. I get that this is not the preferred design by many, but the writing has been on the wall for some time now.
Personally, I'm not a fan of the whole "Psionics should be a totally separate mechanic and system for doing mystical stuff that has most of the limitations of regular spellcasting removed, can't be dispelled or countered; and--oh yeah--magic resistance has no effect! Mindblanked? Too bad, you're my puppet bitch!" attitude that seems to pop up around psionics in some circles. Especially since 5e has used the base spell system to represent virtually every other mystical concept or class so far. I mean, why does my divine miracle working cleric need to use the same system as the eye of newt using wizard?
From a business perspective, WOTC does have a system of discrete, pre-packaged, super-natural abilities that can be parceled out to PCs as they rise in levels that most of the customer base is familiar with. I would have hoped they might have labeled the new 'spells' as psionic, thereby giving a means of partitioning them off a little more, but I'll wait and see what the final psionic (sub)classes look like. For me, take a Sorcercer, swap CHA with INT and give them Subtle Spell on "psionic" spells and you would be close. But who knows what we'll get in the final product.