It will, of course, come as a 'solution' to a perceived problem as do all the infringements of human dignity and freedom such as passports.
I, too, am concerned about the signs - animals have been used as the first stage to get us accustomed to the idea. No-one bats an eyelid about getting their cat or dog chipped by the vet I suppose.
In britain the royal society puts out a televised lecture every christmas in which some boffin or other explains an aspect of science to an audience of kids. A couple of years ago I was disturbed to see a leading boffin talking about how he and his wife have had microchips inserted in their bodies and how cool it is that he can put the lights on just by walking through the doorway. His excitement about the technology and being able to play with it seemed to blind him to its potential abuse.
Or maybe he didn't give a shit.

there is no way anyone is putting any micro-chip in the dog who lives with me... not just cos I won't let him be used as an animal experiment for methods of social control later to be applied to people, but also cos it is his body and while I will always care for him as necessary, what the hell right have I to decide that he needs a medical intervention to implant a chip of no benefit to him?
but the tricky thing is that quarantine laws are now relaxed for animals with implants holding evidence of their vaccination history, and people who want to take their pets abroad/bring them back to Blighty might find that chipping is 'convenient'. sneaky, huh...

this is a very slippery slope that we gotta avoid.

you might be walking around somewhere(say) and a cop one block away presses a button and on his screen shows exactly who you are, where you live, your status(?), etc..
-maybe worse-