I've been waiting since the day the first Captain Tardigrade flash came onto Newgrounds for his return. In response to StashBoogy's question, since nobody else seems to have answered it yet, the answer is no. Tardigrades are not actually extremophiles. While it is true that tardigrades are incredibly durable, to the point of virtual indestructibility, they are not true extremophiles. A true extremophile is a creature that has adapted to live in incredibly harsh conditions such as the mouths of underwater volcanoes or the permafrost in the arctic. If an extremophile is taken out of its natural habitat it will eventually die. Tardigrades on the other hand are simply stupid tough, so much so that they are the only known creature to have survived in the void of space without any form of protection. Just because they're tough doesn't make them extremophiles though. Tardigrades haven't adapted to live in any one specific environment and will eventually die if they live in a harsh enough environment for a long enough period of time. Like the mouth of an underwater volcano.
TLDR Version: Tardigrades aren't true extremophiles.