There are several obstacles to widespread adoption of using eBook readers. Most of the obstacles are because of the limitations of the devices themselves; the one obstacle that is universal is DRM.
The purpose of digital rights management is noble: preventing the theft of intellectual property. However, the implementation of DRM inhibits easy readability and is perceived by users as a grab by publishers to prevent what they see as legitimate use of “their” property. Readers are not ready to apply to books the concept that software developers use, namely, that software is licensed for use, not owned outright. Readers of print books routinely lend or sell their used books. DRM as currently implemented prevents this use.
Obstacles built into the devices themselves range from cost of the device to limitations of the display, and the proprietary formats, including the limited capabilities of these formats.
Publishers need to address these issues when selecting books to market for these devices. The Kindle and Sony Readers are superb tools for reading all-text novels but they fail miserably at displaying the complicated layouts of color-rich textbooks. Should they even try? I think not, unless they are willing to redesign the books specifically for these devices, a costly process.