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.
Here is David Karlsson's script (add into Launchy plugins folder: https://dl.dropboxusercontent.com/u/6248132/Scripts/Todoist%20Launchy%20Plugin.zip)