Does the prominent purple means deeper integration with Yahoo as well? – That may not be the case.
Also, the graphic design choice also suggested, more flatter/minimilist design approach in colors/font/UI than before. This could be a good thing.
Font is also thinner, which make sense for retina displays now we have, apple needs to do better than what they do on the font choice for IOS. On retina displays thinner fonts look better than thick ones, since less anti-aliasing is required/desired because of pixel density. Apple has not really take advantage of that in the IOS yet, I hope thing changes too.