Yes! That would be cool: I mean, why should only two (if I'm not mistaken) of the first batch of ponies get to have a baby?
Another thing I would like to see is a Sea Pony with a poseable tale: Kirk Hindman, one of the sculptors of the original G1 line, said that he has a prototype of one of the original Sea Ponies that had a poseable tale. I would really love to see something like that!
That, and I'd be happy to see Sea Ponies resurrected in the G4 line.