A few points on this project. Because Fr. Weber wants to set the Missal antiphons, he must now revise the entire file to make it fit with the new ICEL text, meaning that it could be another two to three years before the in-print version comes out. I've talked at length with him about doing a version only for Sundays and Solemnities and this seems to be where he is headed. As for the offertory antiphons, I suspect that he is using the Gradual here (I know of no other source) but I haven't checked it out.
At the same time, users should know that this edition as it appears will still be useful after the new translation becomes effective. Most of the music stays the same. The Missal antiphons here can continue to be used since there is no legislation that mandates that the sung propers follow a particular translation (there is no mandatory translation of the Roman Gradual propers now or forthcoming, for example), and the permission to replace propers with any appropriate song must also be inclusive of another translations of the Missal propers. In addition, there are vast amounts of this book that apply with any translation, such as sprinkling rite chants, procession chants, and much else.
So this is a wonderful resource, and I hope that Fr. Weber will consent to letting us post his Pschaltide Gradual as well.