Okay, let's go through a few things that are certain:
- No DS9. That was made on Brandon Tartikoff's specific request that Rick Berman create a spinoff of TNG that was completely different from TNG in as many respects as possible.
- No VOY. That was made not only to continue having a TNG-like "flagship" show, but also to provide a strong opening show for the new TV network UPN. Assuming there is still a UPN, they wouldn't necessarily want a Star Trek show to kick it off because TNG has already failed.
- No ENT. Again, it stands on the shoulders of the series that came before.
- Yes, there will be a Star Trek V. And in fact, it'd probably be almost exactly the same. Production of the movies and TNG were almost entirely separate from each other; Star Trek IV was a phenomenal success; William Shatner wanted to direct and he was contractually entitled to it as Leonard Nimoy had directed the previous two (their contracts were tied together such that they got the same salary, benefits, etc.) In fact, it may be slightly more successful as people wouldn't be able to say "Well, I can't be bothered seeing the movie -- I've got the series".
- Again, there will probably be a Star Trek VI as well. They wanted a 25th-anniversary movie to wrap the whole thing up with the original crew. And there's a good chance it will be almost exactly the same as well; possibly they'll be more open to Harve Bennett's "The Academy Years" movie, as it provides more opportunity for a spinoff, but the thing was actually shut down by Gulf+Western CEO Martin Davis because he hated the idea.
- Django Siddig will never be born. He's Alexander Siddig and Nana Visitor's son -- they met on the set of DS9, had a child, married, then divorced.
- Avery Brooks keeps his beard and doesn't stop shaving his head. He only changed his look so that Sisko would look different from his character in "Spenser: For Hire".
- Patrick Stewart goes back to England before the '80s are over. This was his plan if he didn't catch a "big break" in America: go back to the UK, and focus more on the stage.
- Babylon 5 still happens, possibly earlier than OTL. The original concept and outline for "The Babylon Project" was first conceived by J Michael Straczynski in 1986, but it took five years to sell. For a long time it was rejected simply because conventional wisdom said there was only room for one space opera on TV at a time.
- There is some kind of Excelsior spinoff with Sulu. Star Trek VI was successful. George Takei was eager for it. It would've almost certainly been profitable. And there would be no 24th-century spinoffs for it to clash with (which is most likely what killed it in OTL).
- Jonathan Frakes, LeVar Burton and Roxann Dawson don't become directors. Star Trek was in general very friendly with the idea of having cast members direct episodes -- I think everyone who asked if they could was approved except Garrett Wang for some reason. These three are the most prolific directors among the casts, in film and television.
- Ronald D Moore takes longer to break into television. He was discovered as a writer after passing a script onto someone while touring the set of TNG, which got him his first writing job on that show.
- Gates McFadden remains first and foremost a choreographer. Before being cast in TNG, McFadden had been in bit parts here and there but her day job was dance choreography for stage and screen. Without starring in a hit primetime show, it's extremely likely that this arrangement will continue and she'll be primarily known as Cheryl McFadden the choreographer.