Are they actually going to be using NMC or reinventing Namecoin on top of Bitcoin? If it is the latter then ThePirateBay could either deliberately on inadvertently kill Namecoin.
You seem to keep returning (on this thread and others) to this idea of "If something isn't the dominant force in a particular field, it has been killed."
Things can have small or large adoption and continue to be used. Jazz music is not as popular as rock music, but that didn't "kill" jazz. Norwegian Black Metal is not as popular as Jazz, but to some people, Norwegian Black Metal is the ONLY music they'll ever listen to. Same is true of hardcore punk, and all the other sub-genres of punk.
It's like Ian MacKaye said about Dischord Records. "We aren't a failure because other labels sell more records. Some people REALLY like our records. It's like how a neighborhood bakery that makes really good bread for that neighborhood isn't a failure if they don't expand and open other stores."
PirateBay cannot "kill" Namecoin. PirateBay can do what they want. It won't stop other people from using Dot-Bit.
And if Namecoin is spun off into something else and EVERYONE thinks the new thing is better, Namecoin hasn't been killed, it has been evolved.
Namecoin isn't even a currency. It could still succeed as a DNS registrar if the price dropped to five cents per coin. In fact, it's the only crypto coin that is NO threat to BTC. It is a COMPLEMENT to BTC. The real killer app wouldn't be PirateBay using Namecoin DNS. The real killer app would be a BTC-only gambling site using Namecoin DNS.
The real killer app here isn't PirateBay, Namecoin, Dot-Bit, FreeSpeechMe or even Bitcoin. The killer app here is the Blockchain, which came from Bitcoin. Davi Barker said it REALLY well on his "Bitcoin Not Bombs" article about FreeSpeechMe:
"While regulators scramble to deal with Bitcoin as a currency, the altcoins march on. They don’t realize that the advent of Bitcoin was not the launch of one digital currency, or even ten. It was the launch of a completely new technology. The blockchain was born, which is far more revolutionary than Bitcoin itself. When regulators finally comprehend that the cat is out of the bag, they will quickly discover there is a whole litter of kittens to herd. One of those kittens is Namecoin...."
http://www.bitcoinnotbombs.com/freespeechme-makes-namecoin-a-game-changer/