Dragon Commander will be released first, so I think Larian will focus on updates for that game first. In the topic Kickstarter ? a week ago Lar said

Originally Posted by Lar_q
@Stabbey: I swear, I literally swear that this is the month for Dragon Commander, really ! New website, new trailer, new everything. We're even going to have it tested in multiplayer at Fragomatic in exactly two weeks. It's taken a lot of time, but we want it to be good, so bear with us. February 15th is the date we are working with here to kickstart the entire campaign for Dragon Commander.


See also the blog post Larian & Kickstarter. Even with Larian considering using Kickstarter to be able to add additional things to Original Sin, it wouldn't necessarily delay the release, since that could be done while they continue to work on the main features.