In response to some of the replies,
The average magazine file is ranging (as of my writing this reply) 250Mb-350Mb.
But take into account i subscribe to visually heavy periodicals, like National Geographic, Popular Science and Esquire, for example.
Please take into account I use this baby a lot. So much, in fact, i think i would have to categorize myself as a heavy user. For reference purposes i'll include a break down of how my space is broken up:
In periodicals alone i have quite a number of Apps, some with active subscriptions, some without, but they (the above mentioned triumvirate, Time Magazine, New York Times, Wired and others), account for around 2 Gb of space.
I also have some games, not many, not very heavy (GTA: CTW, Monopoly, World of Goo, Angry Birds, Cut the Rope, Zombie GS, PvZ HD, Contre Jour, Risk, Solitaire and others), but they account for around 2.5 Gb of the allotted 14 Gb.
The productivity apps (Numbers, Keynote, Pages, Penultimate, Procreate, SkethBook, GoodReader, and all their files -which i use heavily for work-) account for the biggest chunk of space, taking up around 3.5 Gb.
Then there is the 2 Gb of photos i carry around (that, i guess, i can do without. Although i admit, i enjoy soooooo much looking thru my sunny beach vacation pictures while i trudge thru my work week).
Last but not least, there are probably around 1 Gb worth of apps that i use for my day to day meandering (Facebook, Twitter, Flipboard, TED, Stanza, etc.)
Together, that makes 11 Gb of usage, without a single song or video.
I have iTunes Match, and an iPhone so i don't really have a need to carry music on my iPad.
Movies and TV shows i do carry around sometimes (Netflix doesn't cover the series i watch, and i am from a country other than the US so HBO Go is a No-Go -same as Hulu-).
So i have 3Gb for my TV shows, and any sort of wiggle room that i might need for downloading new apps. I have +4Gb of apps that are just sitting in iTunes, waiting for their turn at bat (mostly games, i uninstall some to reinstall others and so on).
And that's my iPad in a nutshell. I have a plethora of other smaller free apps that i use, that i didn't throw in because they are not very representative (space wise), but like i said, i'm a heavy user. I haven't timed myself on the iPad, but by the end of the day the battery is usually at least down to 60%, which implies 4 hours use, at minimum during my work day.
I use it heavily for my lectures (not for actually presenting -i have a Macbook for that-, but as my personal notes which i set on the podium as i progress thru the lecture). I also use it for grading, and keeping track of student projects; as well as keeping a great many text books that i require CONSTANTLY during my courses.
Ok, so maybe i'm not in the target audience for the 16 Gb. But it is the entry level iPad, and does account for the majority of iPads out there. Maybe eliminating the 16 and sticking to 32 Gb is a stretch, but 16 Gb (14 Gb allotted space) is still small for comfort, at least for me.
I found this little tablet integrated itself so neatly into my work life, that i now find 16 Gb suffocating.