Cost is a product of marketing, true, but also supply and demand. As newer and greater come out on the market, costs drop dramatically on products that have already been out for consumption.
I've got to say although I'm not a big Apple fan the IPAD is getting to look better and better. I hate that it is connected to a service and hope that will be rectified at some point. I have a feeling (well more than, but I can't be real specific) that there will be competitors to follow on the color format. I sat at a meeting where a group of people just happened to have many of these devices and was most impressed with the Apple (those who know me well will know how hard that was to say).
I am a bibliophile and really like to have a paper book in hand, nothing else really does it for me, but going to a color format opens up media possibilities that I might consider (magazines, newspapers, etc.) that I might not otherwise consider buying. I hate just having B/W displays when technology is so much more advanced than that. My GPS is in color why not one of these?