Given how much of Mandalorian S1 took place in deserts, I'm kinda hoping for a change of scenery in the Obi-Wan show - as in, sure, he starts on Tatooine, but is called away elsewhere for a one-off mission. Because even if Mandalorian S2 mostly takes place on other planets than Nevarro, I don't expect it to drop its largely Western/desert aesthetic, and between that, Jakku, and Planet Burning Man, I'm getting pretty darn tired of desert planets in Disney's Star Wars.
If, however, the Obi-Wan show is just two hours/four eps of Ewan dicking around on Tatooine, I doubt I'll bother to subscribe for a month of Disney+ for that alone; I'll wait for another Star Wars or Marvel season release to watch them both.