I believe this has been fixed in the current subversion branch.
For what it’s worth, I would strongly advise using TVs to manage meta content, because it’s much more flexible and fast to use.
I’ll limit the discussion to meta-keywords and meta-descriptions for the time being, and pass on the debate about the intrinsic value of keywords (or lack thereof) in modern search engines, especially the big 3.
First, create [*meta-keywords*] and [*meta-description*]:
[*] Type: textarea
[*] Default value: the following, where "...default..." = your base set of keywords or your standard site description
Why do it this way?
Let’s say you really are concerned with managing a few key landing pages, and want all child pages to inherit the same values as their parent documents. With the solution above, you get that. Plus you don’t have to worry about messing with remembering to set a description manually for every page in your site (or keywords, for that matter).