It looks like Minecraft Pocket Edition 0.8.0 won't be ready by Minecon, as head developer Johan has just announced the bad news. "0.8.0 is not yet done. Hopefully out by the end of November," he said on his Twitter account. Previously, all we knew about Pocket Edition 0.8.0 is that the update would be released before the end of 2013. The delay until November is probably due him and nearly the entire Mojang team flying out to Florida for Minecon 2013. See the original tweet at the source link below.
Update: Mojang developer Tommaso Checchi has replied to this post on Reddit, saying "Look at the bright side, if we kept the deadline we would have had to skip on some things. Minecraft is quite different from "usual" games where you have a fixed output you want, and a delay means it's farther away… with more time, we can make it bigger!"