>> Mobile phones won't replace computers, but increasing penetration amongst the poorest in developing countries, and increasingly capable handsets in developed countries (and developing countries) will make them a colossal juggernaut. Many of the really big changes, especially social changes, will be caused by mobiles.
> This was already true in 2010, so it doesn't even count.
This definitely wasn't true in 2010. On June 1, 2010, Steve Jobs proclaimed that the post-PC era had arrived, and was promptly ridiculed for it by the industry and media. Massive social changes caused by mobile phones have only occurred this decade, as the gig economy has exploded and places like India have 10x'd the number of citizens with internet access.
>> For any definition of 'success', there will be more tech startups reaching that level in the 2010s than in the 2000s. For example, there will be more than four startups of Youtube/Facebook/Twitter/Zynga proportions.
> Wrong.
Huh? Of those 4, Facebook in 2009 was the most valuable at $10 billion. Now there are 20+ private unicorns with that valuation, as well as dozens more that have IPOd in the last few years. How is that prediction wrong in any way, shape, or form?
>> Hence, starting up will become a more attractive career option, though well-meaning family will still say "at least finish your degree first".
> Wrong.
>> An international deal, of the kind that was aimed for at Copenhagen, will be reached over the next five years, though it might not be far-reaching enough to limit warming to 2 degrees in the long-term. (Despite the failure of the Copenhagen talks, it appears that world leaders almost universally recognize the need to take action over man-made climate change, though the various political problems will remain hard problems). China may not be part of such a deal, though the US likely will. Environmental disasters will begin to increase through the decade, as will disasters that are probably not caused by anthropogenic global warming but will be blamed by it anyway; this will provoke more of a push for action.
> Wrong.
Again, this is correct. The US did enter the Paris Agreement, and has not actually formally withdrawn yet as it is not legally eligible to do so until November 2020. "Environmental disasters will begin to increase through the decade, as will disasters that are probably not caused by anthropogenic global warming but will be blamed by it anyway; this will provoke more of a push for action." is an especially cogent prediction.
>> China will not become a democracy, or even make moves in that direction. However the rule of law will strengthen, and some civil liberties will increase. Internet crackdowns will continue, and may increase in severity, and will still be rationalized by porn.
> I want to say the civil liberties situation in China is the same, but I don't know enough about China to comment on it.
Civil liberties have likely gotten worse, but the rule of law has indeed strengthened. Internet crackdowns being rationalized by porn is also correct, as seen in the UK and elsewhere.
As far as ChromeOS and video games go, maxsilver covered those pretty well already.