With Nook Deal, a Hint of Microsoft Hardware - NYTimes.com

If MSFT/BKS market analysts have concluded that, at current course and speed, there essentially is no meaningful-volume/market share future consumer tablet market beyond the iPad and Kindle Fire, the potential opportunity cost of precluding a vibrant multi-vendor, general-purpose Windows 8/RT consumer tablet market (via a low-priced and MSFT/BKS-promoted/subsidized/etc. Windows RT Nook++) may be an acceptable risk

"First, there is the Microsoft investment itself in the new Barnes & Noble e-book subsidiary: $300 million for a 17.6 percent stake, plus an additional $305 million in payments over five years. There is speculation that Barnes & Noble, as a result of this investment, will create new Nook devices that are based on Windows 8, a coming operating system designed for devices with touch-sensitive screens.
Neither party is confirming those plans. If a Windows-based Nook does come to pass, it will put Microsoft in a delicate position with all the other companies making Windows 8 devices who have not been blessed with a Microsoft investment. Will Microsoft favor Windows Nook devices in some way because of its investment, perhaps by getting more deeply involved in the integration of hardware, software and services?"

With Nook Deal, a Hint of Microsoft Hardware - NYTimes.com