I'm not sure about "must have" - while I have a personal list of necessary features (that leaves me happy on my Blackberry) I'm of the opinion that the only real "must have features" are the ones that the Nokia 3310 had a long time ago.
However there's a few potentially big features. LTE is one - it's not massively interesting right now but I think if/when network coverage improves it could be. NFC is another - right now it's software that needs to catch up, but after that more phones need to have NFC in them. And I'm sure there will be others that pop up in the near future.
However there's a few potentially big features. LTE is one - it's not massively interesting right now but I think if/when network coverage improves it could be. NFC is another - right now it's software that needs to catch up, but after that more phones need to have NFC in them. And I'm sure there will be others that pop up in the near future.