I'm intrigued by the idea of IPFS - but it seems to have some significant limitations...
Everything you store there is basically 'public'. So you can only use it for things you want to make public. Which is probably fine for sharing but not so much for storage like Dropbox does. And once you put something out there you lose control over it. There's no reasonable guarantee it will remain available, you can't retract it, you can't restrict access, etc.
It's also a bit like bit-torrent in that if people stop "seeding" then it's lost. I've added a number of ISOs to IPFS that I was thinking could be a good solution for archiving old software on. But they're now no longer available.
I'm also not sure how much of a big deal "copyright protection" is. Proving I own the copyright of something isn't the hard part it seems but rather enforcing it - which IPFS can't do.
NOTE: this is my understanding from what I've seen - if I'm wrong please let me know rather than simply down-voting me...