Due in no small part to this, I've been putting very sporadic hours into Sublime Text. At this stage, I'm not sure what it's future is. The two paths are to either get over the hump, and get it done with the new UI, or to officially stop development work, and release the code as is as open source.
While I'm sure that many would welcome the project as open source that we really feel a lot better with something official even if we have to wait. Look at how well TextMate has done since it went open source. (hint: not well) The developer went through a similar problem with development and couldn't get over the hump to release a new version everybody was waiting so patiently for. Perhaps instead of going completely open source you could move some of the functionality out of the main project into some kind of plugin system and then let others contribute to those external components while you focus on the core functionality.
I can imagine that this is a rather complicated project and that maintaining it yourself is a big challenge.
Sublime has saved me countless hours during the past months and it would be ashame if it were to wither and die.
Thank you for the product and I hope you will find the motivation to get over the hump and find joy in the development.