Or maybe it was the other way around. Who knows. But ultimately, the break up has happened, and I think the [Hawk] series and Neversoft will be all the better for it (they've been dragging their feet on the Hawk innovations for a while now).
Joel Jewett, Neversoft CEO and awesome drinker of beer (he's seriously a rad dude, every time I've interviewed him over the years he's always had a beer on him and greeted me with one as well), gave the departure news to a local newspaper, somewhere in the US stating of walking away from the Hawk series: "It's probably best for the franchise ... it's time for someone else to add fresh ideas to it".
Of course Neversoft still have their billion dollar new development franchise to worry about now, and Guitar Hero World Tour seems like a good fit for them (On a side note: Neversoft/Activision - please release more metal tracks... please).
As to who will be stepping up to the Hawk series grip tape, that information is yet to be revealed, but with the critical success of the first Skate from EA (I'm not sold on the sequel after dabbling with the Xbox 360 demo), we can at least expect (or hope) it won't be more of the same.