Yes Airfoil is awesome, I have used it since it was conceived. Adjusting the latency is a great feature. It will more than likely be the way around if Apple does any major changes with the protocols and or device requirements.Airfoil is capable of adding a lot of magic to the mix. For example you can manually adjust the delay per device to compensate for speakers with a longer lag. I have an airport express connected to to my Sonos Play:5. It will airplay to all of my Sonos speakers with about a 3 second delay. With Airfoil I can use all of my Sonos and Airplay speakers together and still stay in sync.
I don't expect that Apple will allow this versatility natively.