This recognition bookends Mark with two recognitions of Jesus. Do you remember the first? All the way back in chapter one, Jesus is recognized by...a demon! The demon said, "I know you are -- the Holy One of God!" (1:24). Mark is letting us know that demons and Gentiles recognize Jesus, so we should, too.
In between these two recognitions are two others -- first, God recognizes Jesus as his Son (9:7, with a call to "Hear him"); then, a blind man recognizes Jesus by faith (10:46-52).
So, we already knew that the spiritual realm knew who Jesus was (God and the demons). Now, Mark shows us not only that faith enables us to recognize Jesus (blind man), but the power of the crucifixion also enables us to recognize Jesus (centurion).
In a sense, this represents the apostolic mission. To the Jews, Jesus was the Son of David (10:46-56) whose messianic authority was grounded in mercy (not strength). To the Gentiles, the message of Jesus was accompanied by signs and wonders. The result of both was that people came to faith in Jesus and recognized him.
The scarcity of recognitions of Jesus also says something to us. If, across this long of a gospel, Jesus was recognized so few times, we may be diligent to observe how he taught us to be able to recognize him -- in his authority and in his identity, by prayer, fasting and repentance with watchfulness.
Are you finding yourself like the masses who missed Jesus? Or are you "hearing him" (9:7) through spiritual practices? May I suggest something? The liturgical season of Lent begins this Wednesday. We are not a liturgical church, but there is nothing wrong with borrowing from practices that are designed to help folks move closer to Jesus. One of the hallmark practices of those who observe Lent is fasting. I wonder, during that time (roughly mid-February through March), if you would consider incorporating a time of fasting into your life, in order to be drawn deeper into prayer and repentance, to come to recognize Jesus more fully.