jamesh is going to probably fall off his chair when he reads this, but I'm in complete agreement with him on Pidroid (or whatever cute moniker we collectively decide is appropriate). I'm frankly surprised that Jelly Bean (and to a lesser degree, apparently Ice Cream Sandwich) will run at all, even on a 512 MB Pi, much less a 256 MB model. It will be interesting to see what "Android runs on the Pi" actually means, given the typical 1+ GHz, multi-core, 1+GB RAM hardware on which Android ICS/JB currently actually runs (a Samsung Galaxy SIII I routinely use slows to a crawl several times a day, and not due to network/cell bandwidth limitations - the UI can just go to molasses sometimes). About 6% of all Android devices are running JB according to Google's analysis of the past month's network traffic to sites they track, which extrapolates to somewhere less than one percent of all Internet traffic.
The Play Store apps that allow running Python on Android depend on Scripting Layer for Android (SL4A), which only allows you to edit and execute scripts and interactive interpreters
on the Android device. These scripts have access to some of the APIs available to full-fledged Android applications, albeit with a greatly simplified interface that makes it easier to get things done. There's a big difference in the performance of scripts and interactive interpreters and that of native Android apps, and the incomplete support for all Android APIs means that some things just can't be done at all via a Python script/interpreter.
Per the Code.Google.com site for SL4A
, it's designed for developers and is alpha quality software. That's really not what you want kids starting out learning to code to be working with unless they're the type of wunderkind who are already developing their own alpha quality software via a full PC-based SDK (and often better than many commercial offerings, which admittedly isn't a very high bar, in some cases). Perhaps these scripting apps could be attractive to students, but there are a lot of moving parts that might come off the wagon at any time.
As I've posted elsewhere, running some Android apps on the Pi will be disappointing since they're designed to run on touchscreen devices. Yeah, you can run them with a mouse/trackpad and keyboard, but that's not what they were designed to use, and the user experience is fundamentally different for touchscreens vs. mice/trackpads/keyboards. A significant number of the more interesting apps require multi-touch displays, which aren't anywhere on the horizon for the Pi, AFAIK - no one has even integrated a single-touch display with the Pi, IIRC.
Then there's the motion-controlled apps that require a full 3-D/3-axis accelerometers that no one has announced have been integrated into a Pi. I'm not saying these things are impossible, they're just not easy or cheap to accomplish. How about the lack of integrated cellular data hardware that many apps require because of their mobile focus (yes, USB dongles exist - not very compact and robust, especially if a USB hub has to be added), and there are associated battery issues that crop up if you're actually going to take a Pi mobile.
Since it's not being made public, Pidroid is obviously Not Anywhere Near Ready for Prime Time and given the limited resources available needed to make it so, one would turn blue holding their breath waiting for it. As jamesh asked, just exactly what do people expect to be able to run on Pidroid anyway (particularly given the hardware constraints discussed above), especially where there are functional equivalents already running natively on the Pi on Linux?
If you're really hard over to use Android on-the-cheap, just snag one of the "n minus one" generation Android tablets that have been released as little as a few months ago that are being flogged on clearance sites (as have every previous generation of such devices). If nothing else, it will make a nice VNC display through which you can control a Pi via its touchscreen and on-screen keyboard, or a Bluetooth keyboard.