Cyan cares a lot about delivering their vision. If they believe they need another month I fully trust them on that. I much rather they take their time and get it right than rush it out for some arbitrary deadline.
As a small indie company, Cyan has proven themselves to really care about the games they make. The depth and detail they put into their worlds are astonishing. I'm not at all worried about Obduction.
Slightly disappointed? Sure, but I'm not concerned at all about whether they will deliver or not. It just means I have a bit more time to play some other awesome indie puzzle adventure games that have recently come out while I wait!