There is a facebook page for the Nationals Obedience. I think it is GSDCA Obedience 2014. You can ask to join for all the up to date info. Most everyone on there will do other stuff too, so even if you are only interested in agility join anyway.
Generally, agility is early in the week (Monday thru Wednesday). There is usually a day for all breed agility and then two days of GSD only. Obedience is later in the week, usually Thursday and Friday and has always just been for GSD's.
As of now I plan on being there for herding, agility and obedience.
I bet the premium won't be out til July or August but the FB page will give us heads up.
URO3,UCD Aleshanee Windridge "Kayos" CD,TDX,RE,CGC,HIC,TC
PTE,AG2,AN,URO3,UCD Xtra!Xtra! V TeMar "Havoc" CDX,GN,RE,CGC,HIC,TC,BH
UACH,URO1 Tidmores Rising Star Lydia "Mayhem" CD,BN,AX,OAJ,NF,RE,HT,TC,CGC,
Lucky, Wolf, Max