Good morning Bob,
To date there are 8 travellers, with 11 places remaining. I think it will be included in 2014, all the one off tours have proved popular, Will will be able to offer more insight on this towards May time when the second edition brochure is due out.
I've just read your Vietnam and Cambodia review, I think I'm going to have to book myself on this tour sometime soon! 🙂 Glad you had a great time,
Kindest,
Ben