That's a bummer then.
I don't know why they're even bothering with the 8.1 update 1 really, it's a farsight from what they've shown at build, if anything it just leads to disappointment, it's a poor showing really.
I haven't seen the leak, but 8.11 does not have start menu or windowed metro apps. That will come in a future update and is why it was in a different part of the conference.
If you look at the MS videos of the update in youtube, they aren't windowed and only have a close and minimize button.