כשהוא נועל את נעליו, הוא אומר: ברוך שעשה לי כל צרכי
As we have previously explained (see this) birkot haShahar describe all the activities (mini activities) that we do when we get up in the morning as we prepare ourselves for the new day. The Berakhot help us to discover God's hand behind each small act we are able to perform: opening our eyes, standing straight, stepping on solid ground, being able to walk, etc.
Today's berakha corresponds to the wearing of the shoes.
"When he wears his shoes he says: Blessed are You haShem... Who provided for all my needs."
In the Talmud Shabbat 129a the rabbis explained that a person who does not have shoes should be wiling to sell everything else he has in order to buy a pair of shoes. Shoes are a primary element of protection for our bodies. The epitome of a needy man is a man without shoes. As seen in this bearakha having shoes is equivalent to having all our basic needs covered. This is why when we wear our shoes in the morning we say this berakha, thanking haShem for the privilege of having everything we need.
Today, at least for most people reading this email, shoes are not a luxury. Our problem in the morning is not if we do have or don't have one pair of shoes to wear, but rather which one of the ten pair of shoes we own are we going to use this morning. It is extremely difficult to value something while we have it. And especially when we have it in such excess. If this berakha many years ago expressed our sincere thanks for having shoes, today this berakha should educate us -privileged humans living in the affluent 21 century- to not take our blessings for granted. Being thankful and appreciative to Whom has given us so much.
Because shoes per excellence are leather shoes, during the days that we don't wear leather shoes, Yom Kippur and Tish'a beAb, this berakha is not recited.
If you want to understand what having one pair of shoes really mean, please watch the movie: Children of Heaven, the story of a little Iranian boy who lost his sister's shoes and scared of telling his parents who cannot afford another pair, he and his sister try to manage without asking any adults for help, taking turns to wear the same shoes.