[ge0rg]

I would really like to know on which devices the host emulation API will be available at all.

[vshastry]

Most Android devices with NFC will probably support the API assuming they are running or are upgraded to KitKat.

Edit: including link to source: http://developer.android.com/about/versions/kitkat.html#44-h...

"Support for HCE is already widely available on most NFC controllers, which offer dynamic support for both HCE and SE transactions. Android 4.4 devices that support NFC will include Tap & Pay for easy payments using HCE."