Hi Andrea, and as they say at Mickey's Not So Scary Halloween Party (MNSSHP), "BOO to you!"
MNSSHP is one of my all-time favorite Disney Special Events and I always plan my travel to coincide with this spooktacular Magic Kingdom Party.
The dates for 2012 have not yet been been revealed, but I am expecting an announcement any day now, as historically, tickets have gone on sale late March to early April.
Last year, the party took place on select nights between September 13th and November 1st which should give you an idea of what to expect. My best advice is to begin checking
Mickey's Not So Scary Halloween Party site regularly, as the information could be posted at any time! I would also recommend visiting the
Disney Parks Blog and subscribing to their feed via email (top right corner of the page in the orange "RSS" box). If dates are released, they'll be the first to report the news so if you're signed up via email, the information will be sent right to your inbox.
Best Wishes,
Amanda F.