A facebook friend posted on this coming Sunday:
… sometimes I feel liturgically bitter that Divine Mercy Sunday has kind of overrun the Second Sunday of Easter. I understand that the Gospel is about mercy, but the focus on Divine Mercy has taken on a life of its own, and I am not sure it is as well connected to Easter itself as it could be. Maybe I am simply being a liturgical curmudgeon?
Perhaps I was more bothered ten to fifteen years ago. Not really anymore.
First, we already have monikers attached to some seasonal Sundays. Easter 4 is for the Good Shepherd, Advent 3 is Gaudete, and Lent 4 is Laetere. We get distracted by pink on some of those and First Communion maybe on the other.
Two, I think the more artificial assignments–like Catechetical Sunday or Planned Giving Sunday are much more bothersome, especially when the Scriptures are ignored in favor of an alternate and possibly non-liturgical notion.
Importantly, mercy is an excellent fit for early Easter: the echoes of Good Friday, the forgiveness of Peter, bringing Thomas along, plus the readings from Acts. Divine Mercy is a facet of popular piety that has links to liturgy. We could do worse.
I look upon it as the beginning of a development in worship and devotion. Maybe it has lasting power. Best of all, if people begin to see mercy as a quality not only to admire or about which to be thankful, but to actually practice. The imitation of Christ always leads us onward.
Catholic Sensibility 
In my neck of woods, that is not the case. I remember a few years back another twenty-something (at the time) was complaining about the lack of interest among priests for this devotion. A few scattered parishes will have something tomorrow.
That said, I think the Novena attached to Divine Mercy Sunday helps unite the Triduum to Low Sunday as it is really an extension of the intercessions for Good Friday found in the Roman Missal. Inspired by this Novena, in my own personal prayer life, I celebrate the Octave of Christmas by starting a Novena on December 24th for peace and end on Jan 1st for the World Day of Peace.