How long do you think it will take OEMs to update their device to Jelly Bean?

So as a lot of people know, it's taken decades for OEMs to upgrade from 2.3 to 4.0, which is understandable because of the major differences from Gingerbread to Ice Cream Sandwich, so for that I'll give them a bit of slack. But I'm guessing a lot of you remember having to wait to update from 2.1 to 2.2 and from their on 2.2 to 2.3, and even then when there weren't HUGE updates it took them quite a while to update, but Android devices should be getting better in that respect. So what do you all think? How long will it take OEMs to update from 4.0 to (at least) 4.1.1?