Ok. So I'm between keeping my NC and rooting it, or keeping my ipad2. Bought both, trying them out till return date runs out. Rooted NC sounds awesome. My only concern is with possible memory. Can I put in a bigger card?
Out of the box, the iPad2 is going to be a signifigantly better experience.
Since you haven't "rooted" your NC, you have in no way seen what it can do. I suggest getting a uSD card, and following one of the guides in the root section on loading Phiremod onto the SD card.
Reboot your NC with the card in it and take a look and see if you like the full Android Gingerbread OS. This will give you a much better idea of what a fully opened up NC can do. Keep in mind, running on the SD card does make it a little slower, so it will only get faster if you install to internal memory.
By doing this, you don't risk violating your warranty and will be able to return you NC. Just power down, take the card out and when you reboot, you're back to completely stock.
B&N will not take back a rooted NC. Depending on your level of computer knowledge, you certainly can unroot it or put the stock ROM back on, but I still suggest installing the aforementioned uSD card because it's easier and gives you a much better understanding as to what you'll really be able to accomplish.
FYI,
"Rooting" just means opening up the base OS files so you have more access. Nothing looks any different, you can just do more such as use the Android market and install apps.
ROMs are files that overwrite the base OS, and can make the device look and act completely different.