I love iPad, but for reading books with mostly words I prefer kindle over iPad any day, and having free 3G world wide is a big plus.
iPad is good for reading books with pictures and tables.
Even I don't like e-ink, but I just ordered a Kindle.
Reason:
You can borrow 10K+ ebooks for free, even you can buy it for few bucks. just feel it unfair.
But I will read it on iPad anyway, and give the Kindle to my kids.