Camp Nou is Catalan, Nou Camp was the older Spanish version, although the official name now in all languages is Camp Nou (there was actually a vote on this).
I am used to hearing Noo rather than Now, but wouldn't swear as to my Catalan pronunciation.
The Foster project looks quite cool, and 10,000 more seats are 10,000 more seats. Whether it will do anything to improve the atmosphere is a more difficult question.