I'd like to hear why people want a very fast sync speed. I know quite a lot about this topic and can see direct applications for sync speeds up to about 1/1000th, but at that point applications get a lot more limited.
Up to 1/1000 would be incredible. Hell, a 1/500 for full frame would be pretty damn fantastic. I think people are just commenting on the idea of no sync speed, but they're getting excited about faster sync speed... any improvement is a good one. It's something you don't see with all these new cameras, for some reason.
A lot is happening between 1/160 (real world max sync of 6D) and 1/500; long lenses can be problematic at that slow a speed, normal movement and certainly sports can blur, etc. Having that flexibility would have a big impact on my photography, and I'm sure many others.
Obviously you're going to run into limitations, well before 1/1000. I find (unscientifically), my flashes at full power seem to be somewhere around 1/200 - 1/300 range. So there's limits of what you could do. Many flashes might be down to 1/4 power by 1/1000... but it's still better than HSS.