At a Borderlands 2 panel PAX Prime last month, Randy Pitchford teased attendees with an "accidental" glimpse of an easter egg paying homage to a super-successful indie game. Stop reading here if you don't want to get spoiled.
According to this thread on Reddit, there's a bit of Minecraft in Gearbox's hotly anticpated shooter. Screens from Borderlands 2 show a boxy customization option in the style of Mojang's hit game, along with some very familiar enemies, too. So it's in there somewhere. All you need to do is find it.
(Via Reddit)