Read the joint statement here (published by the White House).
In pertinent part, it says:
"And we are now confident that, without transitioning to a new domestic consumption-based tax system, there is a viable approach for ensuring a level playing field between American and foreign companies and workers, while protecting American jobs and the U.S. tax base. While we have debated the pro-growth benefits of border adjustability, we appreciate that there are many unknowns associated with it and have decided to set this policy aside in order to advance tax reform."
In other words, it's dead and it's gone, not to return.
The Washington Post says it clearly - it's a concession of defeat by Ryan and Brady.
Let's hear it for rationality!