In terms of general content, there isn't much to do and Patch 4.3 didn't contain anything that could keep the masses busy for the time being. A lot of the things you listed, Vidu, are pretty niche, and may not appeal to the masses, in all fairness. There are also others that have already done a lot of what you've listed since 4.0 launch/the content was available (e.g., PotD), so they aren't really "content" for those who have already done them.

I still think it was a mistake to delay Heaven on High until 4.35. 4.3 itself didn't offer enough new, long-lasting content to justify the reasoning for the delay.