The ending implication..(spoilers)

[Gom]

So after playing Claptastic Voyage, I felt like playing BL2 again so I did it. And realised how evil Claptrap sounds in that game..almost like Shadowtrap. Treating you like minion, evil laughs, all the 'Dance for my enjoyment!', etc.

Did Shadowtrap integrate with Claptrap at the end of DLC to save him? I just played BL1 -> TPS -> BL2 and the difference is quite pronounced.

[Kantoor]

I think that's just claptrap being silly, he dosen't actually mean any harm.

[Smaug's Arrow.]

I think you'll come to understand that claptrap never existed but as a clever guise. From the beginning its always been shadowtrap who from the darkness manipulated events to suit its dark plans to destroy all other claptraps as its vanity is so great that it could not rest until it was the last. As there can be only one.

[zverozvero]

Outro implies that shadow protocol took over body, and was only survival, so BL2s one is shadowtrap.
Well, for AI that used to be stewart-bot, Vault hunter and Ninja assasin it wasnt A Must transition from BL1 to 2.
Original BL2s clap felt perfectly fine after BL1, and didnt sound too notorious. Claps product line even in PS felt nicely composed of cute (in Pandoras way) sly, selfish and semicompetent a--hats. And assasin/vault hunter/robodevil didnt overthrow Flynt to begin with, even if digging for freezing minions could be asumed as part of some evil plan.
Whell, here goes nothing... plot twist. They needed antagonist and revelations messing developing previous plotlines, and those went smoothly for 'fragmented psycho-traps mind insides projection' based world. It is good overall, but borrows relevance from previously solid lines.

[Kantoor]

I actually thought the ending implied that Shadowtrap died. Was erased once and for all, and Claptrap survived because... Maybe the fragtrap thing worked as a shield for his claptrap-ness?

[Carmac]

That's what I thought too, Shadowtrap sacrificed its existence so Claptrap would survive.

[zverozvero]

'Not bad not villians' idea of original PS could actually be the stuff. Would be really nice.
Then it may be considered refference (or more like analogue) to 'that movie where boy restores dream land with fantasy'... dont remember name of that film... But idea's really good. Will kinda explane 'duchelocity' part of BL2s trap.

[Osamaru]

Ya, I took it as Shadow Trap sacrificing himself to save Clap. maybe some of Shadowtraps personality still lingers in him.