Extremely reliable sources have informed TLC that the PoA DVD Launch Party will be on November the 18th of this year, which is a day before the DVD becomes avaliable to fans in the UK.
It is apprantly being held at
The Honourable Society of Middle Temple which is in London (pictures of the place can be found on their website.)
Directions to the place can be found
here.
The cast and crew from the film are due to attend.
Source:
The Leaky Cauldron.
EDIT:
I have emailed the contacts at Middle Temple - hopefully we'll receive some sort of response!