Yes, I think they definitely add that song that Edward wrote for Renesmee. I remember reading about when he wrote it and I thought it would be a really cute scene. ^_^ Also I don't see any reason why they shouldn't write it.
Because in the book, there weren't as much Edward-Renesmee moments as there were Bella-Renesmee moments and even Jacob-Renesmee moments. There was perhaps the small part where Renesmee remembers Edward singing his lullaby to her and the time when Edward held his baby so Bella could arm-wrestle Emmett. And..that was it :(
Due to this, some fans think Edward doesn't love Renesmee or doesn't relish her as much as Bella and the others do.
So, to strengthen the clarity of the loving relationship Edward does indeed have with his daughter, they should at least add his lullaby.
Plus, it'd be sweet =)
omg yes they should...I think that they also should put clair de lune as edward and bellas first dance at the wedding!!! They better not put breaking daen in 2 movie...they were thinking about it...unless they already thogh of doing it and im too stupid not to realize it!!