It is new and a I think a lot of Rotella users are like me and have a stock of the older type on hand. I'm going to try Rotella T5 10w30 when I use up the remainder of the 5w40 that I have on hand, or perhaps before that if my curiosity gets the best of me.
It's never been that I believe the 5w40 weight Rotella I've been using to be necessary or even better for my cars. I only went to it to get the stout additive package of an HDEO - and I could only find HDEO in 5w40 and 15w40 on store shelves - when they reformulated the 5w30 and 10w30 oils I had been using [Mobil 1] to reduce their ZDDP additive level a few years ago. I just wanted to keep the same basic additive package that oils had when my engines were designed "for good measure," I guess you could say, and the HDEOs gave me that. I ran some 5w40 and got good UOAs and on road trips found the gas mileage to be basically the same - maybe a couple of tenths of a mile per gallon less, at most, as explained in other posts I've made here about that - so I've run with it ever since.
I think the Rotella 10w30 might be better for my applications than their 5w40 I've been using. I'll have to give up my bias toward synthetic to use it, but I think the distinctions between synthetic and conventional oil coming out of modern refineries are not where they were when I became a synthetic convert 20-something years ago. It might be a perfect blend for me. I intend to check that out.