It´s an interesting topic for philosphical musings. I belive that mind-uploading is impossible, as I don´t see any way to explain consciouness in a physicalist/reductionist way. Contrary to popular opinion, there is no explanation for consciousness, and to how it correlates with the brain.
This is what is reffered to as the mind-body problem.
Also related to this is the hard problem of consciousness.
Another point is that life extension can be achived more realistically through biomedical enginering, like CRISPR, and interfaces can be made directly with the brain using nano-technology,especially something called a neural lace which Elon Musk is working on.
Sorry for all the links, I couldn´t help myself!
Please give me your thoughts.
http://nordic.businessinsider.com/elon-musk-on-neural-lace-2016-6?r=US&IR=T
Yeah consciousness would be almost impossible to replicate, if you watch the prestige the character talks about not knowing whether he would be the one that woke up in the box or was on the stage. So which one was actually the original is still unknown, because to them, before they were copied they both believed they were on the stage.