Is trackback dead? Are comments on life support?

Quoting from Trackback is dead. Are Comments dead too? (plasticbag.org)

I think it’s time we faced the fact that Trackback is dead. We should state up front – the aspirations behind Trackback were admirable. We should reassert that we understand that there is a very real need to find mechanisms to knit together the world of webloggers and to allow conversations across multiple weblogs to operate effectively. We must recognise that Trackback was one of the first and most important attempts to work in that area. But Nevertheless, we have to face the fact – Trackback is dead.

Shelley Powers says don’t throw out the comment babies with the trackbathwater.
Commenters at plasticbag suggest that tagging will supplant both, but tagging is just as susceptible to spam and namespace-squatting, is it not?