I saw this on either espn.com, cnnsi.com or mlb.com but they had the umpiring crews for each series.
For the Cubs/D-Backs, it's:
Ed Montague (CC)
Is this crew good or bad for us? I don't remember any incident with any of these guys during the past year. At least we don't get C.B Bucknor (Red Sox-Angels) or Bruce Froemming (Yankees-Indians).