I think that regulation is something that is inevitable and more and more countries will decide to regulate Bitcoin in some way. But I don't think that regulation is equal to centralization. Bitcoin can be regulated and decentralized at the same time.
Regulation means seting some rules how Bitcoin should be treated, what is legal and what isn't, how it should be fitted into financial framework.
I think that regulation could strengthen Bitcoin and help it to be more accepted, we don't have to be afraid of that.