E-Readers Vs. Mp3 Players

As should come as no surprise, I am an avid reader and an avid researcher. I love the idea of e-books and e-book readers. I love the idea of being able to carry around an entire research library in my pocket (admittedly, as over-sized pocket, but you get the idea). However, I think the execution, as it stands now, requires more than a little work.
An e-book reader is, essentially, an mp3 player for books, instead of for music. There are some differences in function and the requirements of that function, obviously, but the similarities are close enough for comparison and are also close enough to raise some serious questions. Both devices are digital media devices intended to allow you to carry entertainment media in much larger volumes than older, more traditional forms would allow, both devices greatly increase the portability of that entertainment, and both devices can use digital standard formats that have been around for some time now and newer, more proprietary formats. The specific file size of the media in question is also relatively tiny in both cases and the software overhead required is also far from extensive (as well as being well established and fairly standardized).
The major difference between the two devices (aside from the obvious function difference) is that the e-book reader actually does less. The average e-book reader displays text and maybe pictures, usually in gray scale only, and that's about it. The average mp3 player today can play songs and videos, display pictures (usually in full color), and many even have limited text functions (though, granted, far less than an e-book reader, even if the mp3 player were of a size to make it comfortable for that use).
So why does the e-book reader cost more? \
I'm going to compare Amazon's Kindle (currently one of the top ranked e-book readers) and Creative Labs' Zen mp3 player (in my opinion, still one of the best mp3 players). The Kindle, as far as I know, is only available through Amazon and costs $259 US. It has 2GB of internal storage, no expansion slot that I can find in the online documentation (if a Kindle owner can correct me on this, please do so), a 6" gray scale only screen, and dedicated wireless access for instant, online purchase of e-books through the Amazon store. I can buy a Zen at virtually any place that sells consumer electronics and the particular model I'm looking at would range in price from $100 to $130, depending on where I bought it ($130 at Amazon, roughly half of their price for the Kindle). That model comes with 8GB of internal storage plus an SD card expansion slot that would allow me to greatly increase that capacity. The Zen only has a 2.5" screen (completely worthless for reading e-books) but it is full color. The Zen plays both music and videos, displays pictures, and has a limited built-in organizer and a built-in radio receiver. The Zen does not come with dedicated wireless access, but I could purchase an appropriate data package from any wireless carrier in the country for considerably less than $100 a month.
Does anyone else find this disparity confusing?
I realize that part of the problem is the fact that there is a much higher demand for mp3 players than for e-book readers and that higher demand can result in a lower price when it isn't combined with product scarcity, but that only accounts for so much. Higher demand, of course, also tends to increase price, so there is some balancing feature to that demand part of the equation. E-book readers are something of a niche market right now, and that tends to equate to a higher price but they will remain a niche market if something isn't done to address this issue. [As a further demonstration of what needs to be addressed, the average price for an e-book at Amazon is $9.99 while the average price for a song in mp3 format is $.99. As a writer, I fully realize that a novel is a larger product than a single song, but compare the price difference between a CD single (roughly average about $500) and a paperback novel (roughly average about $10, and this is in a novel's cheapest non-digital format) and you can easily see that there is a pricing problem here.]
The portability and convenience of e-book readers means that this market has great potential, if that potential is allowed to develop. Part of what took the digital music market so long to grow (and part of the reason it is still behind where technology would allow it to be) can be attributed to the recording industry dragging its collective feet in that market and doing everything it could to prevent the market from getting off the ground. The book publishing industry is now doing the same thing to the digital book market, but they have even less rational for doing so. The recording industry can at least rely on the relative expense of making music to keep artists chained to the industry. Book publishers do not have that luxury. Modern technology, and especially the internet, makes it so that the only serious advantages a traditional publisher gives to a writer are respectability and advertising.
Book publishers have the perfect opportunity to get in on the ground floor of a new and growing market. They should be throwing their weight behind making e-book readers useful and affordable and they should not be letting middlemen like Amazon corner the market and set the rules. The profit potentials are certainly there, if the publishers have the foresight to go after them.