After watching the Rogue One trailer a handful of times I've got a couple of thoughts.
1 - I love the Star Wars world, and this looks cool. I can't wait to see it.
2 - This seems even more random than before. Maybe Disney is holding out on us and we'll see some familiar characters play a prominent role (Obi-Wan, Darth, Emperor, Snoke, Boba Fett, The Ghost / Rebels crew, etc.) that add to their character development. I don't count Mon Mothma as a character I really care about.
Or maybe these characters will end up re-appearing in other anthology movies taking place in this time frame, or spin off in to a Netflix TV series. Either way, for a first shot at an anthology movie this seems to have virtually no strong tie ins to anything else that is going on. It may be a cool story, but I would have started with a Kenobi, or smugglers theme, or Boba Fett, or probably 25 other interesting ideas with more obvious connections.
I'll withhold final judgement until I see it, but I'll be somewhat annoyed if this becomes a completely random movie without adding significantly to the Star Wars world. Disney is getting a lot of my money - and I'm probably too cynical - but Disney needs to make sure this doesn't come across as a pure money grab.