[Update: Apple acknowledged and fixed the problem. You may once again resume your regularly scheduled updates and downloads.]
From rumblings in the community, it sounds like Apple’s App Store servers have a bug right now that causes newly installed apps or updates to irreversibly crash on startup, even if those apps worked perfectly before submitting to the store. The problem affects a wide number of apps from a whole bunch of developers, and Marco Arment has more details and a list of known affected apps.
We’re looking into the issue, and we assume Apple is too, though it has yet to comment on what’s going on. We’ve heard that Mac App Store updates are not affected, but you might as well be safe than sorry.
For now, it’s probably a good idea to hold off on installing updates for any apps, including ours. In the meantime, try going outside (if you aren’t in the middle of a nasty heat wave) or picking up a good book. We’ll let you know as soon as we hear more about what’s going on or when the problem is resolved.