To the women wearing their heart on their sleeves in this thread (yes, you too Acid

), as heart-tuggingly cute as this may sound to you, when you were 20 years old, in college, living with your parents, would you have been mature enough to make such a life-changing decision? Acid pointed out that hindsight is 20/20 - that's true, and hindsight is only insightful if you or others are able to learn from it - otherwise it's just a dormant memory. So put yourself in the OPs shoes/position and answer the question - maybe you have already, not sure.
I've been in love (shock, horror, I know) on a few occasions and felt the same way freakedout does right now, but I'd have been a little silly proposing to them all.
@freakedout - there are details you have omitted in order to protect your real username - those details are pertinent to this thread and your state of mind regarding this girl as well. You should post under your real username if others are going to get a better understanding of the full story.
Puppy-dog love is such a cliché, but very apt for where you find yourself right now I reckon - it may feel so right, but it only feels that way right now - marriage and proposals are serious things for women and they most certainly don't all see it as a mere commitment of a long term future, as is being implied sort of in this thread. You're messing with her heart if you proposed with no actual intentions of getting married yet - stating you want to marry her in 2011 is all good and well, but you've got a heap of ups and downs to get through until then - getting over those ups and downs are what will make you sure she is the one, and vica versa - not this fresh puppy-dog love that you're feeling at the moment - understanding this part is imo the sign of being mature enough to actually get married. You've got to get over those bumps in the road before proposing, otherwise it's just like playing games with both your hearts. Stating that love will resolve everything is absolute baloney, but it's easier to hear and accept than the truth, which is that love can only get you so far - the devil is in the details my friend.
And to those stating that love is an emotional decision and we should embrace it - yeah sure love is, but marriage isn't a purely emotional thing any longer and is also a two way street. I can only imagine how awful it would be for any female to eventually know that she was proposed to for the wrong reasons, or feel like her fiancée wasn't completely forthcoming about the reasons and his doubt. The sign of a mature relationship in this case would be one where you can talk openly and comfortably with each other about this very topic - if not, you're nowhere near ready for marriage...