To my recollection, this is the second Unearthed Arcana article that's been posted, which is a way for Dragon writers to pitch various houserules. Despite being in the magazine, they aren't "official", and as such cannot be used in RPGA events, nor will they be included in Character Builder. If you want to use them, you're instructed to take it up with your DM.
This time we get psychic support, giving psionic characters the option to "delve" into a target's mind as they make an attack. Delving can only be used with disciplines that target Will, and you must declare that you are doing so before the roll. If you hit, the discipline has all the normal effects, but also gives you an additional benefit that you can change each time. They range from being able to see what the target can, to the most likely actions that the target is going to take, to getting bits of information for the targets mind. You can also opt to perform "dangerous delving", which nets you better benefits--gaining bonus damage, imposing an attack penalty, or preventing shifting--but at greater risk.
Since delving doesn't cost a feat or power selection, it comes at a cost. When you delve and roll a natural 1 or 20, or get an odd number on a dangerous delve, you suffer from mental contamination and have to roll on a table of consequences. You might just be slightly dizzy and suffer no other ill effects, or be dazed and allow the target to see through your eyes, or (in the worst case scenario) have some of your own memories overwritten by the target's in addition to briefly sharing the target's goals, forfeiting control of your character to the DM for a turn (but the overwritten memories are permanent).
These acquired memories and personality traits lead to what is called dissonance, which causes you to take an assload of psychic damage whenever you act in accordance to a memory that you lost or against a personality trait that you've gained. To make matters worse they are cumulative, so if you end up acting against two or more memories and/or traits you'd take twice as much damage. This leads to the likely outcome that delve-abusers explode at some point when pause to consider menu items.
It's good for players that like psionic characters and gambling their character's sanity, but not so mkuch for players that get attached to characters or groups that constantly have long-term campaigns.