I agree with all the above.
It is hard to contribute meaningfully as a non-hacker. These lists require one signup, and then to use them meaningfully (ie: like a forum), another signup on nabble. I am essentially treating them like a forum via nabble. Something on the Inkscape site would be excellent!
The wiki does provide some means of input, but it's very limited to the pre-existing structure (or lack of). I don't know how to create new pages, even if I can create new sections within a page. Again, another signup to do that though. Wouldn't it be great if one signup did both a forum (replace the email list) and the wiki?
Wouldn't it also be great if that one login let you update your extension on the Inkscape extensions section? Or the same login would let you comment on other extensions?
I agree that it would be great to have a menu item that led you to http://extensions.inkscape.org, and let you click on the page to install them. Like xpi's for Firefox, they could be a zip or gzip archive just renamed to make the association with Inkscape work. They could contain all the same stuff (.py and .inx files), just packaged up with a simple zip and rename operation. Clicking on the file would put it in /{home}/.Inkscape/Extensions on Linux or /Application Data/{username}/Inkscape/Extensions under windows (don't know about Mac, but you get the idea), and the rest would just work. Juca, I think the autoupdate option is a good second step, but lets take first steps first.
As I mentioned, this would allow a leg-up for would be developers. People who don't have a clue how to program C/C++ let alone use SVN/CVS or Docbook could be given another way in. Heck, some people who can't even write scripts could package existing scripts.
When I studied marketing, there was a lot of talk about barriers to entry. Companies like M$ often use barriers to entry (like file formats) to further a monopoly position, but are now learning the hard way that barriers to entry lead to trouble. In the open source world, barriers to entry just discourage contributors. Yes, the Contributor/User ration is low, but surely some of that comes down to making it easy to get in.
Lets take down the barriers to entry for Inkscape. One login for http://forum.inkscape.org forum , http://wiki.inkscape.org wiki and http://extensions.inkscape.org extensions . One central website that aggregates content that's out there, but that also attracts people to put their content on it in preference to starting their own blog. One click extension installation.
Rygle.