Bukkit is what makes most Minecraft servers fun for a vast majority of people, yes I guess just because Mojang is taking over the project doesn't mean it'll die, but due to a conversation I overheard on a Minecraft server, Mojang has successfully gotten rid of Bukkit because they want more people to play vanilla Minecraft, but vanilla is boring, it's like Skyrim with a texture overhaul mod, it's not something you notice if it's installed, but you really do notice it if it's not installed.
And because most of the staff at Bukkit have resigned, who is going to take over? Who are the people that will fill the gaps? Mojang are swimming in money and want more of it and by getting rid of Bukkit, they'll have more of it, but not for long, Minecraft is already losing a vast majority of players, and now that because of EULA or whatever it's called, the big servers as well as the small ones are suffering and will continue to suffer until they are gone or someone successfully saves them with a project or an idea to make money. And the way it looks, no one is succeeding. Minecraft has had a great run, but thanks to the common emotion of greed, it's starting to die, the things that make it so fun to play are dying, after that, Minecraft will eventually die. And the only way we can stop that from happening is if someone succeeds with a project to save Bukkit servers.