Hey everyone, I can confirm that people looking into a fix for this.
In the meantime, a possible workaround is to add -usecoherent to your command line. The GW2 wiki has instructions on command line arguments if you're not familiar with this process.
Some of you may be running into a separate problem. This does not apply to everyone in this thread, but please note that the game may not launch or work properly after we release a new build if you use a third-party program, due to possible incompatibilities.