SpaceX is already ahead of them with their Raptor engine component testing.
SpaceX Ready for Raptor Engine Components Testing at Stennis
24APR2014
http://nasawatch.com/archives/2014/04/spacex-ready-fo.html
Now take a look at performance numbers.
http://en.wikipedia.org/wiki/Raptor_%28rocket_engine%29
Raptor is being designed to produce
8,200 kN (1,800,000 lbf) of vacuum thrust
—6,900 kN (1,600,000 lbf) thrust at lift-off
Compare that to the Russian RD-180
http://en.wikipedia.org/wiki/RD-180
Thrust (vac.) 933,400 lbf (4.15 MN)
Thrust (SL) 860,568 lbf (3.83 MN)
And compare those to the Blue Origin BE-4.
http://www.spacenews.com/article/launch-report/41901ula-to-invest-in-blue-origin-engine-as-rd-180-replacement
Bezos said during the press conference that the BE-4, which will generate about 550,000 pounds of thrust, is based on the BE-3 that powers Blue Origin’s New Shepard, an experimental suborbital rocket that takes off and lands vertically. In addition to the Atlas 5 successor, the new engine would be used for a future reusable orbital launcher Blue Origin plans to develop, he said.
Two BE-4 engines generating a combined 1.1 million pounds of thrust at sea level would power the new rocket’s first stage, Bruno said. The current Atlas 5 first stage is powered by a single RD-180 generating close to 1 million pounds of thrust.
This is no plug and play rocket engine. Going from earth-storable RP-1 to cryogenic LNG is going to be a big step for the Atlas V. Whoever sold this as a replacement for the RD-180 could sell ice to Eskimos.