Update 2: Everything's working now. Huzzah!
Update: HBO has removed that Jelly Bean line from the "What's new" section. So much for that.
The HBO Go app today got an update to support Android 4.1 Jelly Bean, as well as "performance enhancements and bug fixes." Unfortunately, it doesn't actually support any devices that are actually running Jelly Bean. Go figure.
As you can see above, you still can't install HBO Go to the Nexus 7 from Google Play. Or, on a stock Galaxy Nexus -- also running Jelly Bean.
We're hoping HBO just needs to flip the permissions switch in Google Play to allow the devices that actually are officially running the version of Android it now officially supports. But until then, we're just gonna stick to Netflix, we guess.