Getting married is nothing to entered into lightly (I say this as one who is married). It is more than just making your relationship 'official'; it's a declaration of a commitment before God (if so inclined), government, and everybody. It is the announcement of the creation of a family, and you may find that having a cohesive family identity makes life much simpler for all parties involved (despite the weeks of dealing with the bureaucratic BS).
Some might argue that your relationship with your partner is your business, and to a degree; that's true. However, when you get married, you are making it SOCIETY'S business (thus the certain benefits and privileges that come with getting married as opposed to just 'in a relationship'). It is a total, unequivocal, and unassailable bond. (At least, that's what it's SUPPOSED to be...perhaps I'm a bit of a romantic, but that's what marriage is to me.)
Now all of this is just my opinion, of course. I'm not so arrogant as to attempt to define your own relationship to you. But we do not exist in a vacuum. Our societal interactions are geared towards recognizing a family, any confusion regarding that (particularly with kids) will follow you pretty much wherever you go.
Taking his name is not for your benefit, it's actually for everyone else's.
Oh, and congratulations. May you and yours have all the happiness life can bring you.