I didn't know they were even this close to releasing it but 1.5 to 1.6 is going to be a Major change and will most likely be incompatible.
They are going to make a lot of needed changes though, but all old template will not work.
Here's a link to a slide show on it: Lifting The Lid On Joomla 1.6
They are going to make a lot of needed changes though, but all old template will not work.
Here's a link to a slide show on it: Lifting The Lid On Joomla 1.6