EA and DICE have announced that Battlefield 3 & Battlelog will be down for maintenance today at the following times:

3pm - 8pm GMT
4pm - 9pm CET
7am - 12pm PDT
10am - 3pm EST

EA had announced on 31 May that today's the day that they would release a massive Battlefield 3 update which included a significant amount of rebalancing (reducing suppression and resolving the M26 Dart issue) and a colourblind mode for Console users amongst other things.  The full list of changes to be included in the update can be found here.  However, this hasn't stopped speculation that Battlefield 3 Premium or the new Close Quarters expansion will be released as the downtime will last until one hour prior to EA's E3 press conference.

Personally I don't find either of these options likely at this stage, EA is due to show both Close Quarters and Armoured Kill in playable form but that hardly suggests that CQ is ready for release.  I also don't think it makes sense that EA would launch BF3 Premium an hour before they announce it at E3; for my money this is just another update, albeit a sizeable one that may well lay the groundwork for both the new expansion and the release of the premium service.  After all, EA accidently released the premium trailer earlier today (see below) then pulled it obviously as it wasn't meant until after the E3 announcement.  So again, why would you release Premium before you announce it and why would you keep the trailer hush hush, that would be the worst marketing campaign ever.  Then again, this is EA we're talking about.