This is what I worry about; it feels like only a matter of time. The only seeming way out of this is to have a law enacted that ensures consumers' rights are truly fully protected; but then, that seems like a nearly impossible goal to achieve.

A general lack of understanding about copyright law among people in general really doesn't help the issue. Here's hoping we can both stave it off a bit longer and find a real solution.

Well, that's true of most DRM, eBook and otherwise. Still, I'd personally rather not buy DRM'd books and strip them, because that still appears to support DRM'd books from a sales perspective.

RTF is a better choice than either, if you really want to keep things simple. But neither really adds up to ePub at this time for anything that includes images at all. Then there's metadata, text reflowing/resizing and so forth.

Actually, ePub files use XHTML and CSS. They already have the ability to plug in a DRM layer (with no specific standard demanding a certain sort at this time) and include text reflowing and resizing (while keeping images at the same size up to as large as the screen in question allows). They also track page numbers based on the original book's page size. So effectively, it's probably the implementation you're asking for.

PDFs are great on computers and some devices, but don't always work as well on eBook readers. Other formats such as ePub have better capacity to reflow and resize text while keeping images at a single size; reflowing text on an eBook reader often causes errors in PDF files. It depends on the reader in question of course, but if we're looking for an industry standard, it should be as widely compatible as possible, and ePub would fit the bill better than PDF for that.

ePub is a really good choice. Aside from the fact that it's an open standard, it has the option to plug in any DRM the publisher wants to use/write for it. Hopefully they eventually learn better, but since for now they won't settle for anything that doesn't include a DRM option, that's an advantage for it. It's specifically designed for reading books on an eBook reader, including keeping track of where the pages actually change (when reading at different zoom levels). I'm honestly a bit surprised the industry isn't already switching to it.

That said, I'm not fond of the Adobe Digital Editions DRM that it tends to come packed with at the moment on DRM'd books. The required software is not very good quality. The eReader style DRM is at least a lot easier to work with. (Of course, DRM-free remains the ultimate goal; at this point I pretty much only buy DRM-free eBooks anyway.)

Another choice that might be better geared to students is the Entourage eDGe. If memory serves it was created with students, especially in science fields, in mind. It has one ePaper screen and one tablet-esque LCD screen, and apparently it's received decent reviews from students, though I have no personal experience therewith.

Recent article
Official site

Excerpt from article:

The enTourage eDGe is the first device to merge an e-paper and LCD screen to create a dual-screen device that combines the functionality of an e-reader, tablet netbook, notepad and audio/video recorder and player in one inclusive device. These two displays work together to allow students to access and enrich information in a way that they previously couldn’t. Students can access their textbooks and make notes in the margins or highlight text while they simultaneously look up further information on the subject via the Web on the LCD side.
[...]
The two screens of the enTourage eDGe interact so that users can open hyperlinks that are included in an e-book text and view the content on the LCD screen, or ‘attach’ Web pages to passages in an e-book to be referenced at a later point. Additionally, as the enTourage eDGe uses E-Ink technology for easy digital reading, images will appear in gray-scale on the e-paper side of the device; however, users can load these in color on the LCD side, ideal for viewing colored charts and graphs from course materials. A built-in camera and microphone captures audio and video content that users can store and play back later. Included Documents To Go software makes Microsoft Office documents available for creating, viewing and editing for notes or school papers. The enTourage eDGe runs on the Google Android operating system and backs up all content on enTourage Systems’ servers for safe keeping. The device folds a full 360 degrees and orients its displays horizontally or vertically, to view as a book, single screen, or prop up laptop style.

Setting aside questions about Texas itself for the moment, I wonder if this will cause other states to go to greater lengths to separate their curriculum from Texas's. The curriculum change got a lot of opposition in Texas, and I can only imagine it would get a far greater amount in many of the other states, especially the more liberal ones.

Agreed wholeheartedly. There are things that I want to keep private; those things do not go on the Internet. There are things I don't mind companies knowing. eBay knows my name and address and for a while I had a credit card on file with them (I still do with PayPal). Similarly, I don't particularly mind Google knowing what I search for... any more than I mind the local bakery knowing what goods I like. Nobody complains about a bakery keeping track of sales (Hmm, the elderly seem to like xxx while kids like yyy. Let's sell xxx on Sunday afternoons, and yyy weekday after school hours!) but Google keeping track of search records (People who search xxx often are looking for yyy. Let's use yyy ads on sites that match xxx keywords.) is seen as evil. (And yes, I'm aware that's an oversimplification, but I think the point still rings true.)

I guess you can call it selling my privacy if you want, but I don't know that it's really my privacy if it isn't something I particularly wanted or needed to keep private in the first place.

Sorry, that one highly reduces your odds of getting laid too.