It usually takes just a few days to sync completely through all DC’s, but Google has been doing things a little out of pattern as of late so there is really no way to tell how long THIS PR/BL update will take to show up on all DC’s.
Keep an eye on Matt Cutts blog, he will probably update us all Monday or Tuesday depending on if he recognizes PREZ day and is working or not.
I estimated that this PR/BL update was going to happen on Valentines day, so I guess I wasn’t that far off (only 4 days).
I didn’t see any PR or BL all day on my sites, but now it looks like it is showing on the TB nearly every time I open a new window or refresh the page.
It’s kinda strange, my homepage got PR=3 and is 3 months old. Some of my internal site pages got PR=4 which is weird as usually the sub-pages and directories have less of a PR than the index page.
Well, another 3 months or so until we see another PR/BL export from Google (unless they change again). If you are not happy with the changes this update brought you, keep building links and promoting and hopefully next time you wont be disappointed.