I think:
2013 will make 1080p screens standard
2014 will make better batteries & cameras standard
2015 will make more storage (64GB local) standard
And by 2016 we'll all be needing more RAM...
All that to say that there's always going to be something to improve so I doubt they'll ever peak.
2013: battle of 1080p screens and processors
2014: cameras like you said
2015: more ram, also much more features integrated into software/bye bye android and welcome new OS from manufacturers
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