I know this question was directed towards Tom, but I will attempt a reply (he is apparently away):
Do you know if the Catholic church views JW baptism as being "in the manner prescribed by Jesus"? The Watchtower CLAIMS that JWs baptize "in the name of the Father, and of the Son and of the Holy Spirit" but many here would disagree with that view.
They don't. The baptism is not carried out in the name of the Father, the Son, and the Holy Spirit. And even if it was, the JWs see the Son as a created angel, and the Holy Spirit as an impersonal force so the intention of the baptismal formula would not be the same and therefore invalidate it.
Bottom Line: Are active JWs viewed as "separated brethren"?
Being that baptism is how we are brought into the body of Christ, and that only members of that body are Christian, an invalid baptism does not accomplish this. If JWs are not part of the body of Christ, then they are not Christian, and they are not "separated brethren."
Also, can "separated brethren" go to heaven?
It is possible.
BTS