I have already made the switch to apple, and it is important to stay with a system once one has started with it. For me and other biblical studies people, this comes out in the Bible study software that one buys. Bibleworks and Accordance are about equal in quality, but once you start with one, it is better to continue investing in that program. Both of them run poorly on emulators. I have already invested quite a bit in Accordance and don't want to switch to another program.
Doing things away from home requires many books that are just not available digitally or easy to get at the library. For instance, all of my Akkadian stuff would need to be taken with me. These books are heavy. Adding a full sized laptop to the bag would give anyone scoliosis. When I first started thinking about this problem, I envisioned a netbook. Dell sells netbooks for about $300 (http://outlet.us.dell.com/
My pdf library is large, and growing. Pdf's are an important component of all of my research not only are jstor and EBSCOhost the first places I look for the most recent articles, but also places like archive.org provide a good selection of important historical approaches. I hate reading on the computer not only because of the backlit screen but also because of the shape of the screen and the posture of one at the computer is unnatural for reading long documents. There is an important post here about the desire for the paperless academic (http://bbibb.wordpress.com
One of the things Brian mentions in his post is the Kindle. The Kindle DX is almost the ideal piece of equipment for reading long pdfs. It has an eInk screen that is almost like reading a real book, and is about the size of a normal printout. The two things that really make the DX unlikely to be a great resource is note taking and price. Kindle will not let you take notes on a pdf. Also I would complain about the slow page turning. The eInk screen is a physical machine and so turning pages on it actually takes a lot of little colored balls to move around. But the biggest factor against the DX is that with the same sized screen as the iPad, and with a lot less functionality, it is the same price. (This post here, mentions some early failed experiments on Kindle and college. But I think this talk tackles the shortcomings more directly).
The netbook is a better notetaker than the iPad will be (even with the silly little keyboard), and the Kindle DX is a better reader than the iPad will be. But the iPad does both and is the same price as a DX. It is also lighter than a new laptop, and considerably cheaper than a new MacBook.
The last point that I would like to bring up is my new work flow. I have been thinking with the more papers that I write the more it dawns on me that I need to change the way I go about writing papers. There are so many great academic programs for Mac that there is no reason to do the entire writing process in Word (or any other word processing program for that matter). For some examples see here http://homepage.mac.com/kv
-research and initial note taking on Papers on the iPad. Then sync with the macbook. If I am taking notes on a document that is not in PDF form I can use evernote which automatically syncs over the net.
-Arrange thoughts and notecards on Scrivner and write the rough draft. (With Papers, I use Bookends for bibliographic management).
-Export to Mellel for formatting and final proofreading.
This way, I use the iPad for what it is best at and Beth can now have access to a computer to check her email and look stuff up on line.
I wrote most of this before we even got the iPad, but as I finish this up I am writing it on the iPad. I think overall this criticism is correct: the iPad is for content consumption, not creation. It is the ultimate commuter toy. In some ways I am a little disappointed with iPad (no Hebrew keyboard, and the external keyboard is pretty heavy for not really needing to be), but in other ways the iPad is better than I could have imagined. PDFs are a dream, and it syncs really well through papers, and evernote (which is what I am using to type this). As things move along I think things will improve even more. I don't think that the iPad is for everyone, but for Beth and I's situation right now I think it was the best option.
For a more detailed look at my work flow, see this post.