Well, it depends on the substance of the post. As in evidence to back up certain ideas, or details to back up the way one feels about a certain topic.
With anonymous comments, if its not a blog that I use regularly, and they are asking for email address and other info, I have been known to post anonymously. Maybe a rant anonymous comment, with no basis, could be seen as lacking credibility.

Tamera, I agree with you. If you are making a comment and you want it to be taken seriously you should be brave enough to sign it and stand behind your words. If you don't, then you wasted your time making the post.

Not that this is relevant, but I tend to use the following rule: An anonymous person with credible sources has more pull than a known person with anonymous sources. I also recall that The Federalist Papers were some heavy-hitters writing under pen names, yes?

I agree with you Tam. If you have the guts to say something, then sign your name. Nuf said.

I think it depends on the tone of the comments being left. Honest, constructive criticism that comes anonymously is probably worthwhile. People that just want to tear you down anonymously are basically just cranks brave enough to write a nasty comment, but too cowardly to sign their name.