I hope they won't make Gothic 4, because they killed the Gothic series in the third part for me. I compared Gothic 3 to Ultima IX because that was a horrible successor, too, but when I think about it I have to say, Gothic 3 is like Ultima VIII - not a really bad game, but a shame compared to its precedessors - simplified plotline, not really thought-out virtual world, some major (and in my opinion: wrong) gameplay changes.
So, a Gothic 4 would be the Ultima IX of the series, and that would just be ... evil. EVIL!