I love my new iPad (or iPad 3, or Retina iPad, or whatever it's called). I read on it, watch movies, prototype websites, take videos, edit photos. I'm even sending my Macbook Air to a colleague. It's pretty irrelevant with my iPad. The display's a lot nicer, as well, on the iPad.
That being said, despite Steve Jobs' repeated criticism of 7" tablets as "dead on arrival", every time I use my iPad for extended periods or my younger kids use the 10" bit of Apple shininess, I can't help but think, "Gee, if only this were a little smaller." Yes, it's very thin and sleek, it's light for it's size, and there are countless accessories that position it well for touch-typing or extended viewing, but there's something about the combination of space, size, and weight that make this default choice in tablets less than ideal for many use cases.
I have a Kindle Fire and a Dell Streak, both of which are 7" tablets. I also have a 10" Motorola Xoom. The Fire is great if Amazon's take on Android and their fairly closed ecosystem are your thing. I've passed that on to one of my kids and he loves it. The Dell Streak sits largely unused, stuck in old-Android, orphaned-hardware limbo, which is too bad because the friends, family, and colleagues to whom I've loaned it love the form factor (although it's not exactly a featherweight) and performance. It's a beast, too, in terms of durability (there are no better beta testers for a product's durability than my two-year old daughter or my 18-year old son with Asperger's - if they can't break it, nothing will).
The Xoom is also an outstanding device and its support for SwiftKey (not available on the iPad) makes it the best touch-typing tablet I've ever used. As a side note, SwiftKey is one paid app for Android that is worth every penny. It's predictive text engine rocks and the split keyboard on the tablet version has to be used to be believed. That said, the Xoom is just too heavy and awkward to make the cut. Put it on a diet, give it a Retina display, and I'd never use my iPad again.
Speaking of high-end Android tablets on a diet, I pre-ordered a Nexus 7. I couldn't resist it. I couldn't resist the call of Jelly Bean and I couldn't resist a 7" form factor with better specs and a full Android interface the the Kindle Fire I'd left behind could't match. Maybe it won't be the tablet holy grail for which I'm looking. I tend to save most of my typing for a computer with a keyboard, but do find myself increasingly creating content on the iPad (both visual and written). Perhaps the smaller size will get in the way of occasional typing and frequent sketching.
I don't think so, though. I'm writing this on a plane right now. It's a nearly three-hour flight from Newark down to New Orleans on a little Embraer sardine can…errr, I mean jet. Not surprisingly, there are more iPads than laptops out on the tiny tray tables. And even these relatively diminutive devices are giving people trouble as other passengers recline, stretch, climb out for bathroom breaks, and pass complimentary beverages back and forth with flight attendants. Now a 7" tablet…
I'm not saying that in two years everyone will be using a 7" tablet, leaving their bulky iPads behind like Apple left the 17" MacBook Pro behind in their latest refresh. It seems pretty clear, in fact, that we'll see both larger and smaller form factors. However, no matter what anyone says, size matters and in ways that you might not expect.
There's a reason that Google's first tablet is a 7" model. Part of it is cost, no doubt. I'd rather have a cheap, fast, small tablet, than a cheap, slow big one. There is also a hole in the tablet market right now that isn't being filled by the Kindle Fire and certainly not by the iPad. A small, high-performance tablet running the latest Android OS and UI has a lot of appeal. At 7", the Nexus 7 may not be the best machine for running Adobe's Touch Apps, but it's small enough to fit in a large pocket, whip out for a fussy kid, or use unobtrusively in a meeting in ways that 10" of iPad isn't.
As tablets continue to push PCs out of the consumer market, we'll see that there is more than enough room for different form factors. My money, though, on the dominant tablet size in 18 months, though, is 7". And even if Apple calls it the iPod Maxi to claim that a 7" iPad is still a bad idea, I think Apple will be right there with a competitive device.