Also, I've noticed that the correct link in Y! (I think that it depends much on your category) makes a big difference. In my travel related sites, competitors with old links in Y! directory are hard to beat in Google.

Other than those, I like botw and niche directories.

Likely, these days, link aging is a big factor. And the major directories have the prototypically natural pattern of link ages.

Haha. Because of the absurdly long queues and overwhelming number of neglected categories?

Too funny.

assuming that 'trust rank' is becoming a factor in algos

I would say it is safe to assume that 'trust rank' is a factor. And why wouldn't those listings play a role?

The editorial control over the listing is a nice vote for the authenticity of the content. It would logically follow that "smart spiders" would view quality directories as a feeding ground for quality content.