For a long time Deska had a fascination with Rough Collies - I'm sure its because they looked like him (we have quite a few in my neighbourhood). When we go to the dog club the shelties always end up hanging with each other, and not just because their owners do. I am pretty sure they recognise their own breed, or at least they have an idea of what they look like and so what other dogs look like them.
I know they recognise other breeds because Tully is still a bit phobic about certain breeds - black labs because my neighbours black lab always squashes her and cattle dogs in general since she was attacked by one. She has quite a few goldie friends so I guess she feels safe with them.
But when we go to confirmation shows and Tully meets her siblings she doesnt reconise them as being siblings. We even did training with Tully's sister from a previous litter and I dont think she could tell.