I have finished the Warbreaker and i really liked the book. However, I have to agree with rtm1981 post and some of the points he raises:
I also found Siri's and Suse's relation a bit lacking; in fact the book opens with Siri and by the end of it i feel that her storyline has been sent to much to background. I feel there is some continuity missing to her and Suse revealing to each other that they are in love and altogether I found Suse's character a bit disapointing: he's sudden transformation in the end not totally compensating for it (for example, if he never had spoken in his life, how could he suddenly now how to awaken things? were did he learn to do it?
Also, i found the ending a bit rushed, again missing a closure scene with the 2 above mentioned characters.
In regards to the returned and so on... some questions - if they can not have children, how can the royal familly be descendent of one? Also, if they can shape-change, as Vasher refers in the end, and the royal family can change their hair color because of their ascendents, then why are the Gods not aware of this? and why does Siri's arrival among the Gods and her control of her hair growth, etc, is something no one else can do? Also, the change of hair colour is something the real family loose control of when to excited, etc. If the Gods' body reflects how they think of them selves, why does it seem imutable? At least Lightsong personality changes would suggest some kind of change to his perception of him self! I don't know, it just seemed that some explanations were introduced in the end that don't really match what went on.
Also, what happens to Jewells and Tonk Fah? they simply disappear!
To conclude - I really liked Vivenna's character growth but felt that Siri's character went the other way (shrinking), and was a bit disappointed by the God King's character. I really liked Lightsong, the bad guys (Denth and company), and Vasher. Their world and powers are quite fascinating and interesting, but some things are a bit off (in my opinion) and could be better shapped.
I hope i have raised some new questions has i did not read through all the other posts.
P.S. - I really liked the book