I took the table from the summer of code site and exported it to a spreadsheet to see who has the most projects for this years Google Summer of Code. Here are my results as of 4/25/2011.
I only took the top 25:
| KDE | 51 |
| Apache Software Foundation | 41 |
| Python Software Foundation | 36 |
| GNOME Project | 27 |
| OSGeo – Open Source Geospatial Foundation | 21 |
| Drupal | 20 |
| FreeBSD | 17 |
| The Eclipse Foundation | 17 |
| Blender Foundation | 17 |
| OpenMRS | 16 |
| openSUSE Project | 16 |
| R Project for Statistical Computing | 15 |
| Gentoo Foundation | 15 |
| VideoLAN | 14 |
| Mono Project | 13 |
| The Linux Foundation | 13 |
| The Honeynet Project | 12 |
| WordPress | 12 |
| The Java Pathfinder Team | 12 |
| Open Source Computer Vision Library (OpenCV) | 12 |
| Mozilla | 12 |
| Portland State University | 11 |
| Inclusive Design Institute (IDI) | 11 |
| Point Cloud Library (PCL) | 11 |
| Apertium | 11 |