For me, the strength of Arduino is in the huge documentation, experience and wonderful community.
What I would like to see is something like ATMega 328 + connectors and a sort of "peripherals shield" to add to it.
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Another point is not to go ahead to fast.
I just ended my half year Arduino nano learning and experience to find out that this version may lo longer exist. Then I turn to Arduino pro mini 3.3 V - to find out that is very difficult to find them.
As long as the purpose is to learn, such fast moves seriously jeopardize my efforts.
I welcome MKR series - that is wonderful! But for me, their high cost prevent me to pick them for learning and education purpose.
Nano did a great job in respect to education/learning - in my opinion. It may be somehow obsolete, but cheap genuine units and even cheaper clones along with an wonderful simplicity and versatility - these points are difficult to beat.
If Arduino moves up to target more experienced people, then it may leave the empty space for other competitors - that is ok in the market sense, but is somehow disappointing (in my humble opinion).