At various times people have some ideas they want to explore that don't necessarily need to be made default. Since DB is open source, one of the advantages is that you can open the source and tweak things to work differently.
I don't especially plan to incorporate any of the changes from other branches, since they usually involve breaking changes. Carlo's non determinism branch, for instance, had bots execute one gene per cycle, chosen at random. I see where he was coming from with it, but it wasn't something I really agreed with.