Jesus and Judas were close friends, so close in fact that Judas is the only disciple Jesus specifically referred
to as a friend.  It's possible that Judas may well have been jealous over the obvious intimacy which
developed between John and Jesus both emotionally and physically.  Maybe Judas was the favored one
early on, or that he fantasized about being so.  At any rate, his kissing Jesus on the cheek might have not
have had anything to do with betrayal.  He may have sincerely been saying good-by to his friend, the One
whom he wanted so much to have a closer relationship with.  He'd take that on any level.  

Historically speaking, it's my understanding that during Jesus' day when someone was handed over to the
authorities, an exchange of money was required to make it official, similar to a “citizen’s arrest” with monetary
payment.  Jesus had told Judas to “do what he had to do”.  He was ordering Judas to go ahead and turn Him
over to the authorities and get it over with because Jesus knew he was destined to do so.  Judas was, after
all, the treasurer, and certainly Jesus dealt out orders on a regular basis to Judas who would have been
familiar with the particulars that handing Jesus over to the authorities entailed. Imagine, a ministry so
lucrative that a mere group of twelve blue collar men actually needed a treasurer because of so much money
being filtered through it.  Judas definitely was qualified to do his job and maybe that's where the betrayal
came in; his being more concerned with doing the job right than anything else.  He just wasn't thinking
straight at the moment, and perhaps his jealousy of John was never buried very deeply below the surface.   

Maybe he hung himself because it directly spoke to his dutifully obeying the order of his beloved Rabbi, want
to or not, and he chose doing the job to the letter of the law rather than going with what his heart told him.  
Regretting it so sincerely may not necessarily exclude him from the heavenly dominion to come.  Along with
the remorse, did he ask God’s forgiveness?  Time will tell.

We can't let ourselves get in a place where we're not thinking straight when it comes to Jesus.  If Judas'
downhill slide began with a festered jealousy, and it might have, there's a good argument for putting a lid on
ever being jealous no matter how righteously appealing it may be.  Scripture says that Satan entered into
him.  Harboring a little jealousy surely isn't worth that.

Jesus’ love for us must penetrate our very being, so much so that we would never betray Him, never lose
sight of His sovereignty, never let an emotion sway our priorities.

Luke chapter 22