[vetinari]

> In Windows Phone it is also possible to sideload.

Good to know. I was under impression (since WP7 was a current OS, I admit) that you have to upload to MS/have it signed/download.

> Still, nothing would prevent such stores to offer a server compiler service.

Nothing prevents that technically. However, it would mean a tighter coupling between platform owner and majority store owner, Google probably wants to avoid that. It could destroy the open-source nature of Android, since for now the Play Store is layered above open-source platform; this compiler would not fit there, it would have to go below, into the layer that is currently open source.