This is the first time you'll be able to work on Launchpad as part of Google SoC: last year, it has been released under AGPL, thus making it a free software project. It is done as part of Ubuntu SoC, though, so your project has to benefit Ubuntu.
I invite all students interested in getting some serious experience with developing a large web application to apply with their project ideas for Launchpad, as long as they relate to Ubuntu as well. See Launchpad help or development wiki to get a feeling of what is Launchpad about.
I'll be happy to mentor anyone interested in doing some work on Launchpad Translations. David has already posted a few ideas to consider that will benefit Ubuntu, but if you have your own, don't hesitate but apply!
Deadline to apply is April 9th, so hurry up!