Re: Timeline branching going forward *spoilers*
First Contact' changes Zephram Cochrane, who talks about a future with Robotic Zombies. One could say the universe Picard and crew returned to in the 24th Century was no longer the Prime Universe.
It sure looked like the same universe to me. There's no evidence anything was changed there either.
Sweet dreams are made of cheese
Who am I to diss a Brie?
I Cheddar the world and the Feta cheese
Everybody's looking for Stilton