At this time tomorrow, I will have been attacked by velociraptors.
Future perfect tense is used when talking about the future, but in a historical sense. I know - it makes my head hurt, too. Which is why, when I ran across a sentence with an extra verb in it, my head almost exploded.
I couldn't figure out what to do with it for quite a while, and then I subverted the issue entirely by just removing the second verb. I was so pleased with myself for it that I came up with an excellent slogan.
Will have been subverting future perfect
...Okay, fine. It's excellent to linguists and writers. Everyone else is taking a step back to avoid having geek spilled on them.