There's a beta process to retain root while updating to 1.4.1. I haven't tried it yet. I might wait until the next update to make sure the update block that works in 1.4.0 still works in 1.4.1. Staying one update behind is better than nothing.
In other news, users have been very vocal at the B&N official forums about sideloading, root and bootloaders. It's tempting to think nothing can come from that, but over the past year, a number of Android phone makers have succumbed to the demands of users and walked away from the locked bootloader model. Devs at xda are continuing to explore possible weaknesses in B&N's system in the meantime.
For now, I have a great tablet that does everything I need except USB host (
support that request here), and virtually everything I want. Cyanogen would be nice, but as well equipped as the NT is, debloating isn't an immediate concern for me.