It doesn't look like the original developer is providing access to the todoist plugin for Launchy. Can Todoist create and provide a supported plugin for this application?
Thank you for your suggestion, we appreciate it. We may indeed consider such solution in the future and you're welcome to add a request to our Votebox: http://todoist.com/Vote/
@Stephen, I was wanting the same functionality, and was able to set it up with a simple VBS script as outlined in a Lifehacker article here: http://lifehacker.com/5190601/email-yourself-reminders-from-launchy
This isn't ideal because it leaves your Gmail account info exposed, but it does get the job done. Just input your Todoist email address in the "To:" section and you're good. If you're using two factor authentication with your Google account, remember to set up an app specific password.