According to a German newspaper Rob, Reese and Christoph would be attending the premiere in Berlin at the Sony Center on April 27th.
ThinkingofRob contacted them about the info, here's their response:
Yes, they’re really coming all 3 to Berlin: RP, Reese W. and Christoph Waltz!
We have confirmation from Fox.
As far as I know, Mr. Pattinson will come with Ms. Witherspoon and Mr. Waltz to the premiere of the film in Berlin. Further details about the location and progress of the premiere, will be coming in the following days.
As of yet, there is no official confirmation regarding this info. I'll keep you posted.