Ghostcrawler addresses the biggest point with the most passion -- threat isn't fun. It never has been, and threat stats aren't fun to balance. Personally, as a tank, the most contempt and frustration I have for World of Warcraft comes from my inability to control DPSers who can't stop pressing their buttons for a second. It's just not fun to get mad at unskilled players. Ghostcrawler wants interaction between new and experienced players to be positive, and when DPSers blame undergeared or new tanks for threat issues when they have successfully beaten Ragnaros to a pulp and taken his gear, it doesn't make for a positive experience.
With patch 4.3, threat is going to become largely a non-issue. Threat is being increased to five times damage, up from three times damage. Each tank will be given new active defense cooldowns, much like death knight's Death Strike. Warriors, it seems, will be getting the biggest redesign of the bunch, with rage causing a big problem with how warriors need to spend resources to maximize survivability. DPSers will largely be unaffected and will, in fact, have less time when they have to stop attacking or stop their rotations, because threat will be less of an issue.
Check out the full blog post for more information on the huge changes coming to threat in patch 4.3. There is a lot coming in the future, and we will be testing this stuff heavily on the PTR and have more information when it becomes available.