The current model is struggling and Toyota plans to bring out a much sharper Corolla, which of course will be better in terms of fuel efficiency. Again, as in the case of the new Auris, the use of a 1.5 L turbocharged petrol engine is very likely and also, a hybrid version will be added. The platform of the new Corolla will be used for the new compact SUV (earlier post).
BC claims that the new model will be revealed, in Japan, in June 2011 with the hybrid version coming a few months later.
If the rendering is accurate, then I really look forward for the new Corolla. Otherwise, I won't be suprised since I have been used to the "Corolla = boring to death" practice.