Tour guide is still an incredibly good card even with the Xyz ruling reversal. It has a lot of versatility because it can search Sangan out as well as becoming an instant Xyz Rank 3. With Gold Sarc, you can special summon any level four or lower monster to the field with Leviair Dragon, which is huge in some decks (infernity springs to mind).
I expect a common opening play this format will be summon Tour guide, fetch Sangan, set a back row and pass. At this year's UK Nationals my round one opponent (who made it all the way to the finals, losing out to a Six Samurai deck) was running a Tour Guide plant deck and he made that opening play to me in games one and three. It's actually a very offensive oppening despite the fact that the monsters themselves only have 1000 attack. You have to be really cautious about that Sangan especially if you do not know what kind of deck the opponent is running. Sangan can search so many different cards so if you destroy it recklessly, you will be punished. I've personally experienced it so you can take my word for it.