I suspect people will find it difficult to revert back to W7/8 later on after they have had W10 for some time. MS will likely make it difficult to do.
Make no mistake, MS are preparing a platform on which to sell you “stuff” as well as heralding in the next mega-agenda stage of taking away people’s control of their data. For years the computing world has allowed YOU the user to control your data and put it wherever you like. Store it on your hard drive, store it on a USB drive, burn it to CD etc. The move is now clearly towards getting you to put that data out in cyberspace, onto someone else’s servers where you have no control. It’s not total control yet, but it’s getting there in stages. The iPads were one more step in that agenda. No USB ports to plug handy storage devices in. Everything done over the internet when it needn’t be. This, in the end, will create a massive dependency on the internet. You will need the internet and bandwidth to pull down your photos, documents, music, spreadsheets etc etc. They will make you feel all cosy and secure about having those things kept in cyberspace by “someone else” but one day, an “event” will bring down the internet and all your “stuff” will then be inaccessible.
It is personal choice but I would honestly fight tooth and nail to retain total control of my data and my identity. There is a much bigger picture going on here which people are oblivious to and it will bite them when the time comes if they have allowed MS and other giants to take away their privileges.