To be fair, it would be suprising if Hoi2's update was as expansive as Victoria's, if only because I think Hoi2 was a much more polished game to begin with, even before the expansion. Vanilla hoi may have some bugs, but vanilla victoria's economic system was widely seen as too complicated, colonization too fast, and politics too simplist where democracy was the best: Revolutions made serious inroads in solving all those problems. I just don't think there is that much left to overhaul aside from tweaks in Hoi2, even DD was a bit superflorous.
As far as scenarios go I hold out hope for something completly different. Maybe a 1936 campaign, with ahistoric events, where the Central Powers won WWI and you have austria-hungary, the ottomans, and the Kaiser's Germany running around. (The revolutions converter doesn't really work, and even if it did the lack of events would somewhat kill the feel). A little far fetched I know, but if they are going to make a new scenario I would want something completly different. A nazi victory scenario could occur fairly often in vanilla games, and is easy to set up. Maybe rolling the timeline further forward or backwards would let you do something different.
But really I would pay money just for some more features, some tweaks, and end game surrender events/post war events that made more sense and worked better. $20 for a better hoi2 seems to be better than most other games I could buy on the market now...