It appears Amazon is taking some steps towards making their product more versatile. They've given out "Kindle Kits" to some software companies (including EA) and hope to start rolling out programs soon.
In other news, one of the most hopeful new e-readers the Plastic Logic Que has been put through its paces. The English born device is the product of some 20 years R&D into plastic transistors and the Que is a large, unbelievably lightweight, touchscreen reader.
It naively supports a variety of "business formats" including word and power point and touts barns and noble's online book list for extra reading. However, the Que has proven to be slow, even by e-reader standards, and very cost prohibitive.
Finally, and more to the point of the OP, the Nook has had some friendly hacking going on. Yep, the plucky little e-reader with the Android heart has been "rooted" or given up access to its core menu system.
What does this mean? Well, a couple of inspired folks have started putting Android Apps onto the Nook. Apparently "any app will work" but the programs need a bit of formatting to meet the layout of the Nook. So far Pandora and a small web browser have been converted but the team, an I'm sure more apps will crop up soon.
And B&N's reaction? They seem to like, or at least not care, the idea of 3rd party programming. Since the Nook was rooted, three firmware patches have come out and none of them have touched the accessibility of the core programming. Maybe this is why Amazon is so keen to put their Kindle Kits into developer's hands...