I know it's early but when the 12th Doctor arrives do toi think the interior of the Tardis will change again ou will it stay the same for now?

It will stay

It will probably stay. They redesigned the TARDIS in 2010 because it had been 5 years and time for a change, and the only reason they changed it again this an is because they moved from Upper bateau Studios to Roath Lock and it was cheaper to build a new TARDIS than to déplacer the old one.

Basically: it's expensive and there's no reason for it.

I think it will stay the same because the fans are still getting used to the new interior, it did not change with the genration of the 9th to the 10th doctor.

It should stay. It's too soon to change it. I also think keeping it will give a nice continuation and link from the 11th Doctor era. :)