I'm getting this too, again. It happened last week (right after the patch) and a reinstall fixed it, but a couple of days ago the NW client was lagging badly so I shut it down rebooted and got the 'Trying to update the launcher please be patient' message since then I've tried the new exe in the first post, resetting…
It looks like whatever was done to fix the issue broke it for me: I'm now getting the: 'unable to initialize on demand patching' error that others were getting before the 8/28/2014 patch. I've tried disabling on demand, deleting the contents of the live directories and a number of other tip, but none of that has worked.