I got tired of waiting for someone to build an installer. So last weekend I decided to just do it. My original plan was to copy and modify the Joomla installer. I took a look at the code and it seemed to be quite well structured and modular. However it included a fair amount of code from Joomla itself and hence was quite big. I had also heard about SilverStripe CMS and was installing it at the same time. The installation was a simple one page installer which does a few checks etc. The code was fairly well structured and I decided to use it. It also helped that SilverStripe is released under the BSD license. (which means copying is permitted as long as the copyright notice is kept intact)
It took me a few hours to get this working and generating the right settings file. The installer makes the following assumption (and checks for it also!)
Note that we are not using the Drupal module 'install' mechanism. I'm pretty sure we cannot do this within the Drupal install mechanism. If I am wrong, please let me know along with an example of a Drupal module which does something similar.
I'm not sure what the complications are with regard to writing an independent component installer for joomla!, but i hope to replace the component installer in Joomla with this version in a 2.x release. This approach seems to be much simpler and avoids the copying of the large civicrm directory to the final destination (i suspect most joomla installs fail at the copying step). Joomla! developers, do contact me if you would like to help with this.