Ah, interestingly I just saw this on Windows with no ABIs installed. It seems the error message is a bit confused:
> android create avd -n test_4.0 -t android-14
Valid ABIs: no ABIs.
Error: This platform has more than one ABI. Please specify one using --abi.
For now, I'll probably add a warning to the Console Output if users attempt to create an Android 4.0 emulator without having downloaded the required ABI. I've also already done this for the new SDK auto-install feature.
Letting the user choose between multiple ABIs will probably be more difficult – but if there aren't actually any platforms with multiple ABIs yet, then that feature isn't so urgent anyway