Hello everyone!
Yesterday I finished a gbc dumper that is intended to run under GNU/Linux environments, but it sure will run under windows also as I only used standard libraries.
Currently it's CLI based and supports extracting thumbnails and full size pictures. In the future it will have 3 color palettes (black&white, GB Classic style and GB Pocket style) and a graphical user interface integrating ems-flasher for a complete pic dumping solution :-)
Here's the link to the project page: http://code.google.com/p/rgbcdumper/
Any update will be posted at my blog here: http://rombusevilbones.blogspot.com.ar/ (I will update this post also)
Hope someone find this useful, cheers :-)