The internet is too non-standard to take over all desktop applications.
I don't think complete and total centralization will ever happen, or at least won't happen any time soon. I don't see the option of hosting your own domain on your own server ever going away any time soon. Businesses for example would have to be insane to be so tied up in a single company like Google for all their data access.

We have millions of cases of identity theft every year, and the only reason it's not a big deal is that people don't know about it. Hopefully they pass some laws so that businesses are held accountable and are forced to tell people when it happens. But having everyone's data in one central place is such a bad idea from a security standpoint that I'd avoid it for that reason alone if no other.

None of the current technologies were designed for the things everyone is using them for. It's all hacked-on layers of crap. They need to fix a bunch of stuff before the internet ever completely takes over.

I stopped using Gmail partly because I don't like being advertised at incessantly. ( I think no one else cares about this and it will continue to get worse.) And partly because I don't like the idea of my emails sitting indefinitely on a server somewhere. Google may still have my old emails sitting on backups in a hundred computers all over the country. The chances of anyone reading MINE out of the billions of emails that are out there are pretty slim, but it's still not a happy thought.