This is just an opinion that I think needs stated:

I might not be up-to-speed on web design style, but from a skin consumer's standpoint, what is up with the 300+/400+/500+ pixel high headers on many of the skins I see being sold on snowcovered?  Don't get me wrong, the huge panorama graphics and creative layouts are visual appealing, but what a waste of space from an efficiency perspective.  I'm not sure if this is a current trend or an old trend that won't die ...but whenever I see a skin with almost a full 3rd of the viewable thumbnail (and sometimes more) taken up by some monstrosity of a header graphic, I just skip right past it without even looking closely at it anymore.

There is some really great work being done, but I think skin designers (and page designers in general) need to learn to do more with less space.  Isn't the content supposed to be the focal point of any site?  Sure, you want to have a nice header, but even including the search bar and horizontal menu, any header over 200 pixels is too much for my taste.

... is it just me ...or do people actually like those behemoth headers?

I also agree with you to a certain limit as well. 

I am not one for big headers typically, but depending on the site and layout options there are times where it does work to your advantage.  But in general, I do not like big headers, as I still have a number of users navigating to my site with 800X600 resolution and a big header would kill my site functionality!