XDA Developer forum member, deeper-blue released Android 3.0 Honeycomb for Nook Color. This Honeycomb SDK preview port can be installed on 7 inch Nook color.
What works:
* Graphics acceleration
* Accelerometer
* Wireless
* Touch screen
* Buttons
* Sleep/Wakeup stuff
What doesn’t work:
* Sound.
* DSP (No hardware video decoding)
The whole crux is based on B&N V1.1 kernel+modules+driver (honeycomb emulator images), pieces from CM7, manual patching ARM assembler in libraries and writing ugly scripts to hack around various issues.
The NookHoney01 Image is a zip file. When you unzip it, the image is around 4 GB in size. Deeper-blue used it on 8 GB SD card, but it should work on 4GB card too.