I wanted to point out a few things here.
First, despite the Enlightenment/modern bias against the supernatural, it is undeniably clear that the New Testament affirms that Jesus worked miracles. Interestingly, the many different miracles of Jesus are accomplished in different way. This is clear just from the miracles of Jesus in Matthew 8-9: Jesus simply speaks a word to cure a leper (cf. Matt 8:1-3); Jesus touches Peter's mother-in-law (Matt 8:14-15); a woman merely touches Jesus' garment (cf. Matt 8:20-22). Also, in John 9, Jesus cures a man through spitting on mud, placing the mud on the man's eye and telling him to wash in the pool of Siloam (John 9:6). It seems the various methods of healing are meant to underscore that it is not the technique which accomplishes the miracle--the power is in Christ. The blind man who receives his sight in John 9 does not see Jesus as a brilliant physician--he states, “He is a prophet" (John 9:17).
Moreover, the New Testament is full of examples of the disciples of Jesus participating in his healing work. In Luke 10, Jesus sends out the seventy to preach in his name. They return to him, exclaiming that even demons were subject to them, a likely reference to exorcism (Luke 10:17-20). Jesus tells them that He has entrusted them with spiritual authority. He sas that ultimately they should rejoice not because of their authority over unclean spirits, but because their exorcisms indicate that their names are "written in heaven".
Luke 10:17-20: The seventy returned with joy, saying, “Lord, even the demons are subject to us in your name!” 18 And he said to them, “I saw Satan fall like lightning from heaven. 19 Behold, I have given you authority to tread upon serpents and scorpions, and over all the power of the enemy; and nothing shall hurt you. 20. Nevertheless do not rejoice in this, that the spirits are subject to you; but rejoice that your names are written in heaven.”Likewise, Jesus states that believers will even do greater works than the ones he performed: “Truly, truly, I say to you, he who believes in me will also do the works that I do; and greater works than these will he do, because I go to the Father" (John 14:12).
True to Jesus' words, the book of Acts recounts that Peter healed a crippled man (Acts 3:1ff). Later on we read that the people waited by the road just hoping that Peter's shadow would be cast upon them.
Acts 5:15-16: so that they even carried out the sick into the streets, and laid them on beds and pallets, that as Peter came by at least his shadow might fall on some of them. 16 The people also gathered from the towns around Jerusalem, bringing the sick and those afflicted with unclean spirits, and they were all healed.Similarly, miracles are associated with the ministry of Paul. In fact, Acts 19 contains a powerful witness to the extent to which God's power was at work in him: "God did extraordinary miracles by the hands of Paul, 12 so that handkerchiefs or aprons were carried away from his body to the sick, and diseases left them and the evil spirits came out of them" (Acts 19:12).
In no way do the miracles of Peter and Paul detract from the glory of Christ. In fact, the opposite is true. The miracles of the apostles and disciples of Jesus are clearly meant to underscore Christ's power. Jesus is not only capable of performing miracles himself, he is also able to work miracles through others. Jesus is that powerful!
Now, as regards the story of the mirculously healed nun, it should be pointed out that the Church has not yet declared this a miracle. The Church does not simply canonize people as saints on a whim. Even the case of John Paul II receives careful scrutiny.
The article actually explains that this miracle took place in 2005. The nun has only now come out publicly with her story, two years after her cure and careful analysis.
In fact, the article underscores the caution the Church takes in making "miracle" claims: e.g., in the case of a "cured" cancer patient, the Church waits 10 years before giving any consideration to be sure the cancer does not return. As with other miracle claims, therefore, this will be handled with the upmost caution.
I think it is pretty clear, however, that something miraculous has happened here. This is appears to be an extremely well-documented case and I think it's a safe bet that the Church will indeed rule that a miracle has occurred.
Nonetheless, recognizing the fact that this woman received this cure through prayers from John Paul II should in no way be taken as an attempt to slight God's power. The glory belongs to God. That was what John Paul II would have always insisted upon. Yes, John Paul II was an extraordinary man--but what made him so was that he led others to Christ.
This was the lesson John Paul II always came back to when he himself presided over the canonization of holy men and women. The following is an excerpt from his homily at the canonization of Edith Stein (whose name was changed after she became a nun to Teresa Benedicta of the Cross):
Thus the message of the Cross has entered the hearts of so many men and women and changed their lives. The spiritual experience of Edith Stein is an eloquent example of this extraordinary interior renewal. A young woman in search of the truth has become a saint and martyr through the silent workings of divine grace: Teresa Benedicta of the Cross, who from heaven repeats to us today all the words that marked her life: "Far be it from me to glory except in the Cross of our Lord Jesus Christ". [October, 1988; source]Of course, traditionally one of the major points of contention between Catholics and Protestants has been whether the saints in heaven are able to pray for those on earth. I'm not going to write a long post on that issue. I will simply say this: I think the unity in Christ that we have through his grace is more powerful than the power of death.
So much more could be said, but we can't deal with all the theological issues here...
Suffice it to say, "Glory to the Father and to the Son and to the Holy Spirit, as it was in the beginning is now and will be forever. Amen."