I tend to think that Jesus did exist. He's mentioned outside of the Bible a few times by contemporary historians. Whether he's a prophet or messiah or simply a wise man or an uppity carpenter with radical ideas depends upon your faith.
Personally, I think he'd be shocked that anyone was celebrating his birthday to begin with and then terribly sad that so many have misunderstood the message which is still, despite great effort to the contrary, ever so clearly beneath all the commercial dreck. Ultimately, I think he'd be compassionate toward those who don't get it:
Jesus said, "I took my stand in the midst of the world, and in flesh I appeared to them. I found them all drunk, and I did not find any of them thirsty. My soul ached for the children of humanity, because they are blind in their hearts and do not see, for they came into the world empty, and they also seek to depart from the world empty. But meanwhile they are drunk. When they shake off their wine, then they will change their ways. -Thomas 28
Thomas may not be
Q but it's likely damned close.