The second stream consists of TOS and the officially sanctioned canon up to and including Voyager, but stopping there.
Does this stream include the films?
Of course! Though I am happy to dismiss
Insurrection and
Nemesis, both of which are terrible movies. As is
Generations, really, but the E-D has to go away somehow to make room for the E-E to show up in
First Contact, which isn't a great movie in terms of continuity or what it did to the franchise, but at least it's watchable and fun).
I suppose there are really four streams, the third starting with First Contact of which I consider Enterprise to be the sequel of, and then the nuTrek films are their own slightly awesome, slightly silly thing.
I've heard of this idea a few times before. Is there any comprehensive description of the "First Contact" to "Enterprise" theory, I could find somewhere?
I don't know about some sort of central source which establishes this but I have my reasons. For one thing, whenever they rattle off
Enterprises no one ever mentions the NX-01 in any of the other shows. Some would argue that it wasn't a
Federation starship, so it wouldn't be included... yet it seems to me that there is a strong continuity from "Earth Starfleet" to "Federation Starfleet," so that distinction seems pretty artificial to me. Another clue is in the
Voyager episode "Hope and Fear" where the crew encounters a cutting edge Federation starship sent to rescue them This starship is the
Dauntless NX-01-A. As it turns out (spoiler alert) the ship was a fake presented by an alien with his own objectives. HOWEVER, the crew is in no way flustered by the idea of a starship named
Dauntless labeled as NX-01-A. Now, we know from the
Enterprise letter suffixes, they make it possible for a new ship to honor the memory of an older one by recycling both its name and number. By this logic, we would have to assume the NX-01 would have to be (at least in the memories of the
Voyager personnel)
Dauntless.
So in
First Contact, when the
Enterprise crew throws the temporal prime directive out the window and spills all the beans for Zephram Cochrane, even so far as showing them their own starship
Enterprise through his own telescope, they corrupt the timeline in a big way. I can imagine that "Prime" timeline would have had similar events to what we see in
Enterprise, but with differences. The first warp five ship would have been named
Dauntless, a reference to humanity proceeding into the unknown undaunted by hand-wringing Vulcans. Contact with the Klingons would have happened quite a bit later. But, temporally corrupted Cochrane, influenced now by his encounter with the future astronauts on their "some kind of star trek," suggests the new ship be named
Enterprise instead of
Dauntless.
Enterprise has different missions than it would have as
Dauntless including encountering leftovers of the future robot zombies from the north pole who came along with the future astronauts. Who knows what other differences would have happened? It's a good way to explain away the many continuity differences between the
Enterprise show and the four or five other shows which precede it. (Five if you count TAS... which I do.)
But YMMV, of course.
--Alex