I was trying to make the same decision back before Christmas. I asked my sons to get me a NC. I could still have returned it til the end of January, but decided to keep it. (Although I actually had to exchange it because the wifi had intermittent problems connecting.) The NC is way more hackable at this point. I agree with bobstro. For now, the NC does it for me. If the 7" Asus does come out with quad cores and is only $249, I'll probably jump on that.
As for what you can do with a NC, lots! Some people root, some don't. I didn't because I wanted some of the features you get with the native OS, like reading Nook ebooks in B & N stores. I made my own dual boot card from Racks' directions here
. I really like the flexibility of booting into either the native Nook OS, MiRaGe (CM 7.2) or ICS (CM 9). Using some advice in the USB host threads here
, I was able to kluge together a working headset and make calls through Skype last night.
I also made another SD card that has Miui 2.1.20 on it. You can find the files here
. I used verygreen's instructions for a size-agnostic card here
I'm using a SanDisk class 6 16GB uSD card from Costco for the dual boot card. I have Miui on a SanDisk class 4 8GB uSD card. If you decide to boot from uSD cards, read a little in the several threads about the cards. The faster class cards generally do not work well for booting an OS. And SanDisk cards seem to work better than others. The threads are here
You can also find NC's on ebay from Barnes and Noble refurbished for around $149 shipped. They have the same one year warranty as the new ones...