I would like to launch a flow from an update trigger if a field on the object is set to a certain value. Is this possible? I understand that this is possible with the new Lightning capabilities, but can it be done through the apex code on the trigger?
"Flow triggers" won't be available until Winter 15. To use them, its required that no interaction on the part of a user be needed. For more on this, see the Power of Flows: Advanced Workflow Techniques page which has videos from the webinars and links to other resources. Great series that I highly recommend.