I subscribed to Sling Orange this morning and added the TVE source in Channels. I don't see ESPN or Disney, even though both are listed as TVE at the Sling TV website: Available TV Everywhere Apps | Sling TV Help
"Troubleshoot" tab says notAuthorized for both. But I can watch them at sling.com.
Edit: I can't authenticate on DisneyNOW either, so I guess this is a question for Sling. Sorry, should have checked first.