There is always the S4 Pro.
Just another option if we're not getting an Exynos chip.
Personally I'd be surprised if Sammy used the base 8960 with the 225 GPU.
I just can't see Sammy dropping the 8960 in their flagship device, in the largest smartphone market in the world. I think the S4 with Adreno 320 would satisfy the US market.
Just speculation and hope on my part. My Thunderbolt is still kicking just fine, but I have an upgrade burning a hole in my tech pocket that I saved for the S3 and don't want to be disappointed.