The latest news is in. This is the last season of Gravity Falls. Alex Hirsch tweeted the news not too long ago: https://twitter.com/_AlexHirsch/status/667843799129812992
We still have the last two parts of Weirdmageddon to look forward to, and a 2016 release of Journal 3. We're not done yet on here, but the end truly is upon us. I wanted to let you all know, especially since Gravity Falls' status has been up in the air for so long.
Alex ended his message with "pqxv tbfoa" which decodes to "stay weird"