The word "Hosanna" is a Hebrew expression of praise that literally means, "Save Now!" It was obviously on the minds of those who were in the crowd that first Palm Sunday that the One who they were praising had the ability to do just that: He could save! Of course, likely they were thinking more of Roman oppression than their own sinful oppression, but they were still recognizing Jesus as the One who could deliver them.
As we approach Palm Sunday may we have as much joy in our celebration that Jesus DID SAVE us when He went to the cross on our behalf. Our praise should always be in the present tense, but we should also look back and see what He accomplished for us when He took our place on Calvary's cross. But along with the past we still sing in the present, "Jesus Saves! Jesus Saves!"
And as always, don't limit your praise to just the Palm-Sunday-trough-Easter-Celebration. Every day should bring from our hearts a grateful shout of praise to our Savior for the perfect salvation He provided for us!