OK, I went through to put together a printing history of ArM5 supplements to date. I haven't gone back to check on any changes between printings, though some are obvious (the softcover versus hardcover).
[center]5th Edition Supplements Printing History[/center]
AG0275 Broken Covenant of Calebais: Printed September 2004 ($19.95 MSRP); digital reprints starting May 2010 ($22.95 MSRP)
AG0276 Guardians of the Forests: Printed April 2005; reprinted October 2006
AG0277 True Lineages: Printed April 2005; reprinted April 2006
AG0278 ROP Divine: Printed August 2005
AG0278SC ROP Divine (Revised, Softcover): Digital printing starting May 2011
AG0279 Mysteries Revised: Printed July 2006; reprinted June 2008
AG0280 Covenants: Printed January 2006; reprinted June 2008
AG0281 Mystery Cults: Printed April 2006; reprinted October 2006; then replaced by softcover.
AG0281SC Mystery Cults (Softcover): Digital printing starting September 2010
AG0282 ROP Infernal: Printed July 2006; reprinted November 2008
AG0283 City and Guild: Printed December 2006, replaced by softcover.
AG0283SC City and Guild (Softcover): Digital printing starting September 2010
AG0284 Ancient Magic: Printed December 2006; reprinted November 2008
AG0285 Societates: Printed May 2005, replaced by softcover.
AG0285SC Societates (Softcover): Digital printing starting September 2010
None of the releases from AG0286 The Lion & The Lily through the present have yet been reprinted.