I use the cloud, but its problematic. Data, and more importantly high speed data is not everywhere, Data is not unlimited on my devices, and battery life in general sucks.

I listen to a lot of podcasts, music, videos, etc... I like to have some of this on my device.
-Streaming music takes a lot more battery than just playing it
-Steaming high quality video tears through data

I love the cloud for things like RSS, bookmarks, contacts, calendar, email, social, etc... low bandwidth stuff.

I use netflix, and spotify and lastfm, but I don't relay on them alone.

I have a 64gb n9 and I use all of it. I have a lot of music on it, quite a few games for emumaster, and some of your Playstation games are not small. I have books, and comic books on there to read( a comic series can easily take more than a gig of storage), and I'll put a tv series on there that I like that can be a good chunk of storage.

Yes the cloud is great, but its even better if used in combination with physical storage. That means you can have much more at your fingertips, and more reliable access to it. If tablets are going to replace my laptop, I need storeage and a lot of it.