Like Juan says, DNxHD.
It is effectively lossless at higher bitrates (185+) and 185X (10bit) +
DNX is coming fast forward as a standard and it is cross platform.
And for finishing most colorist export DPX, so I cant really see any point in holding on to the PRORES codec.
I have delivered TV spots to all the nordic channels and some european channels and none of them are tied to PRORES only.
And with DNxHD you dont need to think about the gamma issues that is well documented in PRORES.
DNxHD444 is also becoming a mastering format for a lot of large post production houses around the world.
You can also deliver to most platforms with the animation codec that is a very common codec used by a range of graphic artist.
STig