All of those are short-term concerns. Eventually low-power portable-class computing hardware will be as powerful as typical desktop systems today. Though there

All of those are short-term concerns. Eventually low-power portable-class computing hardware will be as powerful as typical desktop systems today. Though there will likely always be a niche for even higher performance machines. Price will come down with volume and greater competition as the market matures, as it always does. And the OSes will get better as people spend more time on these devices and developers spend more time targetting them and working out the appropriate UI optimizations for mobile vs. desktop modes.