Should I get an Ipad over a nook tablet?

Please respond! Here's my situation:
I currently have a 16gb IPhone 4S and a nook tablet. I use my Iphone for music, email, internet, etc. and I only have like and I use my Nook for all my ereading needs. And I intend soon to get a pair of professional headphones (ATH M50) and a mac pc so I wanted to have a higher capacity music player to hold all the higher quality/bigger music files. Lately, I've been considering buying "the new Ipad" 64gb. If I were to buy it, I will most likely sell my nook tablet and use the Ipad's Ibooks app for my ereading needs. I was just wondering is it useless to have a ipad and also an Iphone? and is the Ipad's ereading so sucky compared to a real ereader such as the nook?

I know the Ipad isnt just an ereader but those are just main concerns. I know Im gonna love all the apps and videos.

ANY response helps! thanks so much!