I'm not actually sure whether the things described in the episode were all the weird imaginings of an unconscious David Sandstrom while knocked out, or whether at the end of the episode it just took us back to the point where Bob and Nina left, taking the clone away for David not to see again until he had become a human being rather than a foetus and therefore making it too late to do anything. That was the point of no return, really, even though the events of the last few episodes were set in motion back at the end of the second season with the suicide bombing that nearly blinded Bob.
The general consensus in the communities seems to be that it was all in David's head, I choose to believe that it wasn't. That's partially because the idea of the series finale of such a great show ending with "then he woke up and it was all a dream" is unbelievably lame, (though at least if it was a dream, it was just the events of one episode, not the whole series or something awful like that!), and partially because it would be better if we get to find out what happens to everyone. Otherwise, the series really ends with the previous episode, Nina whacking David in the face with a shovel and then her and Bob disappearing. The end. That's a cliffhanger ending, you don't end a show like this on a cliffhanger. Therefore, the things described in the episode do happen. Though, hopefully just in the show and not in real life.
A few people have said that the last episode was a bit of a let down. I disagree, but possibly because I don't think it was all a dream. There were things about it that I didn't like though. For example, surely nowhere in the world could it possibly be legal to set up a company that sells the sperm of one man to millions of women all over the world? I mean, even forgetting the retrovirus thing, couldn't it cause accidental inbreeding and all the problems that would come with that? There's no way he could have got away with it. I also wasn't keen on Mayko's random comment about going to the moon being commonplace, mostly because 30-40 years from now, I really don't think that it will be. I groaned a bit too when the flu pandemic turned out to be our old friend the Spanish Flu again. I mean, enough already. There was no reason for it to be that other than for David to be able to recognise it with just a quick glance. And that wasn't exactly necessary, not in the way the story was being told, the whole sequencing thing could have been narrated over in two seconds. Maybe it was jut to tie it back to the start of the series, but again, not necessary.
Despite all that, I really liked the last episode. It's very sad to see ReGenesis end though, I'm really going to miss it.
One last thing that bugged me though, Nina knocks David out, and Bob just leaves him there lying on the ground in the snow, bleeding and unconcious? Bob did? No way. There must be more to that than they told us. Cue fanfic...
So, the last ReGenesis, only one season left of Corner Gas... I'm going to have to find me some new Canadian TV series to obsess over!.