The nook Tablet was probably meant as a feature bump/update to the nook Color. They also probably had a higher end tablet. But that one's BOM cost was too high and would be killed by the Kindle Fire. So they probably pulled the planned higher end one, and rebranded the nook Color 'update' as the Tablet. Just a guess.
I believe the Intel's focus for WindRiver is their software tools. Note that WindRiver already markets BSP kits for Linux for OEMs. It includes debuggers, emulators, and build systems. With WindRiver's tools and Intel's hardware they can have a very compelling Moblin Linux solution for potential hardware vendors.
Because Apple has only one version of software for all markets, regardless of carrier, they may appear to be independent. Yet, this sword cuts both ways. If a big enough customer, e.g., AT&T, says jump, Apple is left with no choice but to make the whole world jump. Apple is responding to one market's requirements by changing software for everyone regardless of the relevance to other parts of the world.
The real story is the Nokia / Intel announcement of cooperation on Atom/mobile products. Intel seems rather focused on Mobilin for MID with a long term strategy for handsets. While Nokia will be pushing their Ovi stores/maps/content with a new UI for Symbian. I doubt that Nokia ever looked on Maemo for more than an R&D effort. Commercially it was never a success nor a viable consumer product - a geek toy yes, a popular consumer product never.
Maemo is irrelevant. The real thing to watch is the Intel/Nokia relationship on handsets - see how that evolves from processor choice to OS.