There's been sales on the DLC, but they're not making a GOTY version I don't think, you'll still have to pick which DLC you want to play. Honestly don't need everything, can skip most of them unless you specifically want the race. Base game also has a fair amount of content to begin with.
And yeah last patch did a lot of changes on the old stuff, made the old legendary lords more relevant compared to new ones, made Chaos campaign less shit, tried to make the Empire a bit stronger when played by the AI(not sure how it turns out) so it's pretty good. Norsca looks great too, I might pick it up at some point, but I think I'll wait for some price drop on TW2 preorder like on GMG or something. Mostly I'm looking forward to Skavens though.