Well they investigate his miracles and if there is genuine miracles then he can become canonized.
There is already several miracles, two of them are well known. One is a French nun cured of Parkinson's disease and the other is the healing of a blind boy's vision. I can't say, I haven't researched it too much.
I personally think it is awesome, I did stay up about 5 hours passed my bed time in order to watch it the Mass. From what I have read on him (I have read a good dozen books on him) he is...a true man and the statement that he was a brain and a half was no joke.