As others have stated, the upgrade scheduled appeared in the afternoon on both my sony utv's w/p4 for 12:20am this morning. I was watching Leno at 12:20 on one and it played a message similar to when your guide gets updated offering the option to watch live tv or take the update. Update takes about 10 minutes and on completion you get a little light show and then it takes you through screens that announce all the feature changes as per number 8. It makes NO difference if unit is on or off as one was off and got the update, the other on and got it.
You may have wait a week if you're on the wrong coast but it appears to be a relatively smooth transition. NOTE: it takes awhile for the guide to repopulate but that's SOP after an upgrade.
Orange County, Ca