Hello Linzi
This is one of the new "active" holidays for 2015 and the first group don't go out until the end of March so nobody will be able to tell you anything about it at the moment.
I went to Nepal with JY in 2009 which then had a different itinerary to this new holiday. All I can say is, if you have always wanted to go to Nepal then you must go for it, I'm sure you wont be disappointed.
I loved everything about Nepal, the scenery, their culture and the food and I want to go back to do this holiday, if not later this year then it will be top of my list for next year. If you do go be sure to do the optional Everest flight (weather permitting), you will get a great view of the Himalayas and, if it's still the same as when I went, you will be allowed to go into the cockpit of the plane one at a time and take a photo of Mount Everest.
Avocet