I'm going to be the negative one here and say that I can't see it having a K04 this time
With the K04 being in both the Golf R and Rocco R and I can't see VW marketing 3 cars that are so similar with the same engine. I just don't see space for it.
My guess would be a slightly tweeked GTI, with a slight power increase on the K03 (say 230bhp) and a few cosmetic changes. Otherwise if it does come fitted with a K04 heart, then a quick map would have you a R killer and VW are obviously fully aware of the remapping capability of their FI engines..
Hope i'm wrong as the ED35 could be a perfect replacement to me if it's right..