Based on feedback from mentors of previous GSOC projects, this year we'd really like our student projects to be popular with the Moodle community, rather than just offering projects which have a mentor. (We'll be working out who can mentor which project later on. If you're willing to help mentor or co-mentor a GSOC project, please let me know.)
Thus, if you have any ideas for new features that would be suitable as GSOC projects, please see Development:New feature ideas for information on what to do.
Hopefully, with everyone's help, we'll be able to come up with lots of interesting project ideas, which will encourage good students to apply to Moodle!

PS For further details of GSOC 2009, see the Google Summer of Code™ 2009 Frequently Asked Questions.