With Starstorm passing the $415,000 mark, a 5th character is on the way for the expansion pack. There are no concepts or ideas read as of this moment, however.
Taken from Starstorm Report #19 by Robin Meijer of Ronimo Games:
"But first it's time for some good news - we have received the funds from this campaign, and after doing a lot of counting, we are happy to announce that we have passed the $415,000 mark! That means that a fifth character will be included in the Starstorm line-up! Right now we don't even know what this character is going to be... But we have loads of cool ideas and will be doing some thinking about this over the coming weeks. Once we've got some concepts sketched up, we'll let you know!"
According to the Starstorm Roadmap, this character is set to be released around Q3 2014, making it the last of the currently planned Starstorm 'nauts to be released.