Tonight, 'Dexter' joins the CBS line-up, with trims of some of the show's more gorier aspects (as well as for language) which were acceptable when the series was first revealed on Showtime.
This doesn't alter the place 'Dexter' has in the TV Universe; the original version of the series is still the official Toobworld entry. In the long run, this is similar to the editing done on many classic TV series so that more commercial time can be squeezed into each half-hour.
The same thing has happened in recent years to 'The Wire' on BET, 'Torchwood' on BBC-America, and 'Doctor Who' on BBC-A and the Sci-Fi Channel. It's when new footage is added to replace key scenes which contained nudity - as happened with 'The Sopranos' on A&E or 'Dream On' when it was on FOX or Comedy Central - that you have to consider these versions to be in some alternate TV dimension.
If this altered version of 'Dexter' proves to be a big hit for CBS, might they try to find some way to capitalize on it? Say, by doing a crossover with 'CSI: Miami'? If the concept of the TV Universe is to be valid, Dexter should be crossing paths with Horatio Cane and his team on cases. Right now, we have to say that they do, but on cases that we just don't get to see on our screens at home.
(The same holds true for other characters like Michael Weston of 'Burn Notice', Sonny Crocket & Ricardo Tubbs of 'Miami Vice', and even 'The Golden Girls' and Dr. Weston of 'Empty Nest'.)