The deadline for the Google Summer of Code is 19:00 UTC on April 3rd.

Please submit your applications now. 

After you submit the application you still will be able to edit it.  So please submit the applications now so that both we and google have some sense of the numbers.   If you submit the applications soon, we still might able to give you some feedback that would help you increase your chances of getting accepted.

Here is the wiki page with ideas for SharpDevelop.