Actually such a device has existed since the late 80s. The datalink reciever was installed in a few F-4Gs and F-16s so that they could talk to each other, and computers, radios, and laser rangefinders did exist that could ground FACs could have used to send target coordinates to aircraft. But because we spent so much money on gold plated landing gear handles for the B-2 and F-22 we ground FACs had to make do with grease pencils. Which we mostly bought with our own money, since the Air Force did not fund office supplies for ground FACs.
I still am angry about how ill-equiped we ALOs were to support the army, and why I'll never trust senior Air Force officers to make rational resource allocations of taxpayer money.
Because we wasted so much money and attention on having a bomber that could have a chance to fly to Moscow and nuke a smoking hole (B-2) and an airplane to stroke the egos of the single seat generals (F-22) we just didn't have the money to spend on supporting the Army. Even if the senior Air Force officers had had the slightest interest in supporting the Army, which they didn't.
Yes, the B-2 can do what the B-1 and B-52 can do in terms of trucking long range glide bombs around. Of course the B-2 is very limited in terms of its ablity to deploy, but since the B-2 pilots are provided with a heart shaped rotating bed with a mirrored ceiling just behind their cockpit it is no problem for them to fly these 30 hour missions. It just costs 5x per bomb to do it. It is as if we turned our nose up at our fleet of Ford F-250s (B-52s) and decided that since we still need pickup trucks after all we'd just convert some Mercedes S550's into pickups.