The Motorola MB866, aka the Atrix 3 here in the states, has just passed through the FCC with all the support needed for AT&T's LTE network. A look at the radios (quad-band EDGE, 850/1900 HSPA+, and LTE) make things pretty clear that this one will sport the Qualcomm Krait S4, and rumors say it has a 720p screen and Ice Cream Sandwich -- which every phone launching now should have.
It looks like a very nice successor to the Atrix name, and AT&T's blossoming LTE network looks to be a good place to put this one. We're not sure how it will fare against the other high-end phones on AT&T, namely the Galaxy S III, One X, and iPhone 4s, but Motorola has a strong following. No word yet on when to expect the Atrix 3, but at least now it's ready to be sold.