I purchased the expanded 2008 Proof set with the bi-metallic Champlain commemorative for another set. After the set arrived I became increasingly fond of the attractive design of the $2 coin. Later I purchased the 2000 Millenium coin with the mother bear and cubs...and the beginnings of a new set were started. There will be no rush to finish the set--and it won't be cheap with the gold editions--but I am setting a rough goal to have the set "up to date" before the 2010 issues come out...
UPDATE FEB. 2012 : For what it's worth, I recently added 2 more PCGS PF69's so that now my set is lacking only the 1996 Silver Pierfort and the 2005.
All of my coins are PF69DCAM except for the 1999 and 2003. As of the time of this writing my point total for all coins of the set-regardless of TPG, has just neared the 7,000 point plateau.