The good news is we have made very promising progress with multiplayer interpolation, which looks like it could have a huge impact on solving jerkiness and jumping of remote units in multiplayer. The progress was so good we are now inclined to include this in the 1.60 version, as it looks we will be able to finish this a lot faster than we expected a week ago.
The bad news is this is likely to delay the 1.60 patch a few weeks - you are already seeing this on the state of the beta patch. While the interpolation is not enabled in it still, it contains some preparation steps which are not well tested yet, and are causing crashes, funny footsteps, visual jerkiness issue.
Please, consider the patches 84391 and newer "highly experimental" again until the situations stabilizes a bit, which we hope should be within a week.
We apologize to those who already expected the 1.60 to be released "anytime" now, we think the improvement we are likely to make within the weeks to come will make the update worth waiting for.