"Weighted list" is a generic term that just means the list organization includes some "weighted" factor--so there are lots of ways to display weighted lists.

43 Things' "Today's Tags" on their home page is another example of a weighted list--sorting by weight count.

What's nice about the Flickr-type list is that it's another (maybe even new--not sure) way to display the weighting in a list. In particular, it allows the list terms to be concisely displayed alphabetically and, at the same time, to visually show the weighting (using the font size).

(btw, Ta-Da Lists also have a nice way to show weighting [gif] that's different.)

I think the "zeitgeist" name is good when it refers to the cases where the weighting reflects what is currently popular or active.

So, part of the question about this is: what parts of that Flickr-type display have to be there to deserve the name? The Flickr-type display is:

-an alphabetical list
-of single word keyword-terms (tags)
-space separated (e.g., it's not one word on each line)
-limited to most popular terms (e.g., top 100)
-with the relative popularity rank reflected in the term's font size

43 Things home page "things view" doesn't limit it to single word terms, and isn't alphabetical. Some site displays subsitute most recent for most popular.

Anyway, I don't actually know what's a good name either!