Is the new revised version of the NAB going to be adopted into the lectionary? From what I have heard, the NABRE is for personal devotion only. The US Lectionary is not going to change.
How fathful is it to the Latin typical edition, the Nova Vulgata? It is probably no more faithful to the Nova Vulgata than the older NAB; which is to say, hardly at all.
what is the difference between the NAB and the RSV-CE? The RSV is probably the closest translation to the Nova Vulgata out of the modern English translations I am familiar with; with possibly the Jerusalem Bible not far behind. I think the NAB is more readable for the average person, but the RSV is perhaps a bit more accurate.
which is superior? Out of the two, I would recommend the RSV, but if you actually read the NAB and not the RSV, then the NAB is better. The better one, in short, is the one you actually use. It is better to have a dynamic translation than a literal translation if you will actually read the dynamic translation.