Where can I find a central repository of all available Arduino libraries? Currently; when I start a new Arduino project with some new hardware, the first thing I do is to look for 3rd-party libraries that bring Arduino support for this hardware.

The first places I look are:


The Arduino Playground
GitHub
Google


Generally I find either no support library or several different libraries (it's quite rare to find only one) in different locations with different levels of documentation, different levels of testing...

Once I have found the library I need (sometimes I need to try several), I download it to my Arduino libraries folder, I use it and I forget it.

I find this process cumbersome:


manual search with different possible options, not always well documented
manual download and install to Arduino libraries
no version control in the process (all versions of a library have the same name and thus cannot coexist in the Arduino library folder).


I wish there was a central repository with all available libraries for arduino, with:


description (supported hardware, supported boards)
source code
documentation
versions


And a tool (Arduino IDE or external) to access this repository at project build time.

A kind of maven for Arduino in fact.

I have seen several discussions once took place on Arduino forum, but it seems they led nowhere:


Arduino Libraries Census and Repository
Arduino Library downloader
Arduino Library downloader (2)


Are there other options, that are made it to something usable (from the community or individuals, why not)?
Since this question was first asked, there is now the Arduino Library Manager, built into the Arduino IDE. There you can search for and install libraries.

There is information about how the library manager works here:
https://github.com/arduino/Arduino/wiki/Library-Manager-FAQ

There isn't however an official website listing the libraries, so I recently created this unofficial site, based on the same data in the Arduino Library Manager:

http://www.arduinolibraries.info/