right now I think the biggest issue is the "Company Store" trend in ereading devices and book formats. If you are not from the US then here is info on what "Company Store" means (and other names which might be more familiar because every country has had it happen and some still have it happening):
http://en.wikipedia.org/wiki/Truck_system
The proprietary book formats are, in essence the analog of when employees of a company were paid in a fashion so that they could only buy from food, materials, clothing, whatever) from a store owned by The Company...at a tidy profit and usually at usury type pricing (keep them fed well enough to keep them hungry so the have to work more). It also kept the employees too poor to find other work options because of the debt they would accumulate with The Company.
"Company Store" reading devices lock readers into that family of readers as they build their libraries. It is a slow innocuous process which people never think about until all of a sudden they want to make a change...well the "debt" to the company is in the form of books already purchased. If, for instance, their device breaks out of warranty then they are stuck either buying another from The Company or lose their probably not insubstantial investment on books when moving to a more open device. This is exactly what Amazon is trying to do, have people so invested in their content before they realize the implications that once they do, people have little choice than to just keep going.
ADE is not really any different but at least they are licensing the format to device makers. And remember Amazon is doing the opposite when they (and yes it was an Amazon decision) refused to allow any other DRM content on a reader if the device maker/brand wanted to add DRM MOBI to the list of formats a device supported. The pointless part of that is if a maker wanted to, all they needed do was to support a 3rd party ebook reading software company in adding MOBI DRM then making sure that software could run on their open device. So far I don't think any device maker chose that route because I think it was already in the wind that DRM MOBI was on the way out. Maybe it was an Amazon gambit to see if any device maker would try that work around then end up having wasted a fair amount of cash, though there is enough DRM MOBI content out there that I still see it as viable, maybe but it's probably priced way over the top.
It's convoluted, complicated and completely anti-consumer the way the industry is moving. Thankfully there is enough free reading material of interest out there that I honestly never need to buy another ebook. So, I just want a reader which stays out of my way when i use it.