Before I begin let me put up a.... SPOILER ALERT regarding the main theory of Jon's parentage... Oh, and I'm going to discuss other POV characters who have died or nearly died.
garion, you posted spoiler in the title. Good job. Readers need to beware. We all read at our own risk. BUT I cringed when I read timothy's post. I bet tim thought it was about little spoilers (like how many men Tormund brought with him) or good spoilers (like Jon got a letter from Arya) or spooky spoilers (like Craster had become a wight). I'm sure tim never thought of Mel saying, "Beware the Ides of marching off to war" nor of Jon shouting, "Et tu, Bowen?"
Eversummer, the initials are different... JC and JS. Yet the phonetics are the same... J and S.
The only way to avoid this is to post SPOILER ALERT: Discussion of the death of a Major POV character in ADWD... and that's even worse!
tim, I feel for you. I do. My first five minutes of reading up on further information regarding ASOIAF introduced me to R+L=J. I'd read through ASOS and not even considered that Ned was not Jon's father. I know that's not even in the same realm of shock with what you read here, but it taught me to watch out what I was reading.
To actually comment regarding the substance of the original post... I think that Jon was surprised when he was attacked because it was the first time that Bowen Marsh showed any resolve to either be proactive or to fight.
I believe that the problem that readers have with the attack upon Jon is that it is the only time where the life of a major hero or favorite villain is in doubt at the end of a book. For example, Eddard, Robb, Bran, Drogo, Catelyn, Jaime, Tyrion, Joffrey, and Jon have all been in dire straits, but all of their situations were resolved before the end of the book in which each of their death/near death happened.
I'll say that Jaime's life, at the end of ADWD, is not in danger. He's not just going to disappear. We'll see him again. He has to confront Connington, Barristan, and Cersei... and probably Tyrion as well.
I contend that neither Theon, Davos, Loras, Jorah, nor Brienne are major heroes nor favorite villains. How much did Theon's disappearance near the end of ACOK bother you? Brienne's lynching? Davos' watery plight? I was interested to know, but I don't think I lost sleep over them.
Okay.... I might have lost sleep wondering where Jorah was during AFFC. I believe that more people were concerned with Arya's blindness than Brienne's and Loras' imminent deaths at the end of AFFC.
Now, what if ASOS ended with Joffrey clutching at his throat? I'd have been a tizzy for five years wanting to know if that little jerk finally got his.
What if ACOK ended with Tyrion being cut open by Mandon Moore? That would have been a torturous two months I had to wait for ASOS.
GRRM loves mini-cliffhangers for almost every chapter, but he has not yet left us a book ending cliffhanger of this magnitude. Jon Snow.
The other problem readers have is that Jon's death upsets everything we thought we knew about ASOIAF.
Isn't Jon supposed to be the personification of Ice and Fire? Aren't the theories of Jon's parentage the most discussed threads in fantasy lit for the last dozen years?
Many of you know that I'm not a fan of Jon (I love the story that his POV tells.), but I figured he's one of the two characters (three, if you think they'll be riding dragons) who will make it to the final showdown with The Other. I figured Jon was safe until ADOS (Is that still the working title of Book Seven?).
If Jon is dead, then who takes his place? Sam? Arya? Sansa? Stannis? Podrick? Ned Dayne? Darkstar? Loras? None of those are going to satisfy me.
Jon has to live. Dying does not make sense.
Ursa, If Jon cannot warg into his wolf at his moment of death, does that mean he's giving up the Ghost?