An S5 GPE would be cool. But will Samsung and Google release one this year ? And if so, when ? I'd bet on it not coming out, until after Google I/O 2014 in June, and ship with Android 4.5
But at that point, I'd just wait a couple months more for the Note 4.
I'd say this: if the Google Play Edition program continues at all, there will be a GS5 variant. It's the one model everyone would ask for.