As far as newer faster cores are concerned ... the ARM A72 which was initially expected at the beginning of next year is apparently going to be with us soon. Mediatek have said that their first tablet chips with it will appear in the middle of the year. Samsung are likely to use it in the Note 5 (Q3) too. The A72 cores are really, really fast ....

Bigger news however is that AMD are re-entering mobile graphics. Apparently they've partnered with Mediatek. Could lead to a further shift away from Qualcomm. Also, it wouldn't be a stretch to imagine Samsung licensing AMD GPUs if they're good.