Deadly haste strike. Dear god. The only thing I can see keeping this in line is that missing doesn't deal any damage...
http://www.wizards.com/dndinsider/compendium/power.aspx?id=10454
One, two, three or four creatures, shift your speed between each attack, 3[W]+Con on each hit and you get a stance that grants you an OA that when you hit you shift half your speed and make a melee basic against a second target.
Also, having now looked over epic I'm a bit worried. Hard to justify the horribly weak epic level augmented at-wills.
The psion had 3/4 that were pretty much in the ballpark (1 die of damage on a power that wouldn't get a damage die as a level 1 at-will) with one that had no excuse not to do two dice.
The ardent was around 2/2 or 3/1 (depending on party compisition).
But the battlemind looks to be 0/4. You'll want one at 23 regardless so you have an Augment 6 option. But you'll need to invest in melee training by epic, because there's no other way to deal out 2[W] without power points. Sad, but I suppose I should have expected this by now.
DISCLAIMER: I haven't done any playesting at epic with psionics, but it's terribly hard for me to see why your at-wills don't scale like everyone else when unaugmented. You don't even have the option of the cheep augment until 23rd, while everyone else gets the basic 2W attacks right at 21. And when you do get it it costs you some power points...