I made a whole theory about it on reddit. I wrote that post at like 1am, I probably was high.http://www.reddit.com/r/doctorwho/comme ... tron_from/
Basically (to those who follow the show)
1) Galvatron is a reincarnated version of Megatron. Same character, New body. hmm. (Which supports all your Clara is Rose theories)
2) Galvatron has the ability to time jump (it's called that) in the original UK comics.
3) In the UK comics, a Bounty Hunter called Death's Head was trying to hunt Galvatron. Well, he failed. He got sucked into the Time Vortex and met the 7th Doctor.
Of interesting note, in a previous Mark Gatiss episode "Night Terrors", the kid had a Cyber Stomper ROTF prime in his room. :3