About 98% of Trackbacks are spam. Obviously that can’t be addressed with a new spec without breaking backward compatibility. (For added humor, see the front page of the Trackback Development Blog.) The charter of the new trackback abandons the only thing that made Trackback interesting, and incidentally one of the things it was created for, content aggregation and category aggregation and other applications that don’t require a link at all. (Essentially a push application of what everyone uses tags for now, it was way ahead of its time.) In the meantime, they’re re-inventing Pingback with XML-RPC replaced by Atom/REST.
Why Features Don’t Matter Anymore. I think similar things when I hear “But CMS X has hundreds more features than Y! Why don’t we have more users?”
I put in an application for a free Sun server to try out for either WordPress.com or Ping-o-Matic, depending on when/if it arrives. Everything we’ve done on WP.com has been Dell thus far, and honestly they’ve been pretty good with the exception of one box that they’re going to replace soon. Our biggest DB server (a Dell 6850) does north of 300 queries per second, but it weighs as much as me and uses a crazy amount of power, which is expensive. Of course as more and more of our infrastructure becomes distributed, high performance boxes don’t matter as much.