Instead of posting (3) three new threads in the same forum, why don't you try the SEARCH functionality to find answers !!! An no one really knows when is the exact date, and all answers are just an expectations. Increasing your posts count this way with definitely gets you banned or at lease you will receive infractions It's not my call, but you should look into the forum rules before posting, and please consider using SEARCH FIRST.
Matt Cutt never reveal any words about the duration of PR updating, it just make PR no sense and unreasonable.
Officially there should be one end of October, as the last one was end of July, but gogle update more regularly than this
Maybe google lost some of it's backlinks and rather than falling to a pr9 is doing some backlink building to maintain their pr10. So they need to wait until the have enough links to keep that pr10 rank. Well maybe not.
I thing every day Google updates PR, but to make visible for users Google exports this to their database every 3 month