Of course untouchable never truly means untouchable if you get a crazy enough offer, but I'll play. The year next to each name is the last season the Diamondbacks have that player under control.
Franchise Builders (Guys you can build a team around):
Dan Haren - 2012 (2013 club option)
Justin Upton - 2013
Stephen Drew - 2012
Keepers (Good players that should only be traded in what's clearly the right deal, but not good enough for the Franchise Builders label):
Miguel Montero - 2012
Chad Qualls - 2010
Max Scherzer - 2012 or 2013
Mark Reynolds - 2013
Tony Pena - 2012
Juan Gutierrez - 2012 or 2013
Hold For Now (Guys whose trade value right now is too low at the moment to justify trading them due to their remaining upside):
Conor Jackson - 2011
Chris Young - 2013
Chris Snyder - 2012 (2013 club option)
Probably can't trade (Due to salary, injuries, etc):
Eric Byrnes - 2010
Scott Schoeneweis - 2009
Chad Tracy - 2009 (2010 club option)
Tom Gordon - 2009
Jon Rauch - 2009
Tony Clark - 2009
*Snyder and Young look like they're sliding closer and closer towards this category
Pack Your Bags (Should be deadline bait unless they want to sign a reasonable deal):
Doug Davis - 2009
Jon Garland - 2009 (2010 mutual option)
Felipe Lopez - 2009
Wild Card:
Brandon Webb - 2010
I think that covers just about everybody except for the spare parts. I'm sure we'll all get into a larger discussion over Webb later, but for now I'll quickly put it as there are several main reasons why not to trade him in 2009... A) Obviously he's hurt which will keep his value down for a while even after he returns, B) This team believe it or not can rise as quickly as it has sunk, C) The team will probably have to replace two starting pitchers this offseason as it is, and D) He's still relatively cheap. Of course, 2010 is a whole other animal which hinges on way too many factors to be settled between now and then.