The name is one, whether "ميكال" or "ميكائيل", But the difference in pronunciation and dialect ..
For detailed answer to a question, must first search about Ten novels and seven readings of Quran.
It is the differences in pronunciation and dialect only (by Arab tribes in antiquity)
the previous verse came "ميكال" in Hafs from Asim novels "رواية حفص عن عاصم",and Came "ميكائيل" in shoba from Asim novel "رواية شعبة عن عاصم"
this wikipedia page about Quran's novels (but only in arabic)
A brief summary of the difference between the novels of Quran:
each verse in the Quran has several readings and novels connected with the Prophet, peace be upon him may be,the difference between them include specific words, or pronunciation depending on the rules of each reading, as well as verse drawing may different from one reading to another.
The differences between these readings is not known except the Special experienced in readings Sciences who received this science by sheikhs and Quran's readers,and studied the Quran by scholars from generation to generation access to the Prophet, peace be upon him may be.
And most of the novels Quran widespread today in most Arab and Islamic countries is Hafs from Asim "حفص عن عاصم"