Next Tuesday 😉
No-one knows. Apple traditionally works to roughly a 6 monthly refresh cycle for the MBs and MBPs but sometimes it can be as long as 9 months or as low as 3-4.
The new Intel chips have only just been announced, so don't expect them immediately, although we know that Apple is working on new designs that more resemble the MacBook Air. That said, they will not be radically different.
No-ones knows exactly when; however there is a good chance there will be a revision by October but any speed increases over the current version will be modest.