How much META information is good for you?

As many other bloggers wrote about blizg I just couldn't ignore it. So I added some META tags including keywords, author, country and copyright, so that blizg is happy and can categorize me correctly. All in all it is a nice and, maybe, actually usefull service. There are some other services where you can search for blog countrywise or in categories like DMOZ or the list at Bloghaus, but linking weblogs via their keywords seems to be a new concept.

Of course the technology has a high potential of being abused. Time will show if the service remains useful.

While I edited my META tags I stumbled over The Weblog MetaData Initiative. Some of their (Or his? Are there any other members than N. Z. Bear?) proposals sounds are suggestive in my eyes, others aren't. So I implemented some of them.

But then, if I look at my page source now, I see a relatively huge HTML header. Isn't this contraproductive while we all try to keep our source code clean and compact? Am I bloating my pages or is this all essential information?

Fact is: Google doesn't seem to give a wet sh** on META tags when it comes to ranking. And there aren't any wide spread services that could make use of all these headers. There have been other proposals for years, like the Dublin Core, and they didn't change the world in any way.
On the other hand, If nobody implements the tags there will never be services to use them. And then: The weblog "community" (poor, abused word) is not very conservative and known to experiment with new and promising technologies. Maybe there will be more services like blizg soon or existing services like eatonweb will add more functionality based on META tags.
I think I will keep all those tags until someone tells me why I shouldn't.