I've heard that the games engine Gamebyro have gone bankrupt which means that there will be no DLC for FO:NV, have anybody else heard this or is it a false rumor?

Obsidian/Bethesda already have the engine so the fate of Emergent shouldn't affect FONV.

There's already an http://www.gamesas.com/index.php?/topic/1140192-emergent-game-technologieshome-of-gamebryo-has-folded-and-selling-its-assets/ if you want to discuss the fate of Gamebryo in general and we also have an http://www.gamesas.com/index.php?/topic/1138694-dlc-suggestions-3/page__hl__dlc for FONV.