As it is official now;
Based of the new TNGA-B platform (the Corolla rides on the GA-C, the Camry and RAV-4 on the GA-K versions), powertrains are 1.0 and 1.5 3 cylinders, including a new Hybrid drive train, where the patrol engine is now a 1.5 Atkinson Cycle 3 cylinder, derived form the new 2.0 in the Corolla (likely by cutting of basically a cylinder), likely to be the most popular engine choice in Europe at least;
Outside, it is rather stylish, and form teh pics it seems the black roof will also make it to the lesser models. Interior is quite neatly styled, I like that e.g. the door cards have also received some attention, and are not the same plain "1 single piece of shapeless hard plastic trim" I recently enjoyed in a Skoda Fabia and VW Polo rental cars.
However, as said in the spy-shot section, the car seems quite tailored behind the b pillar, and the whole rear roof/C-pillar section are very rounded, likely compromising interior space and trunk; There is one photo of the rear seats, where it is obvious that the base won#t fold down (let alone slide like in earlier Yaris'), and head room does not look to be made for overly tall people.