I love the e-Reader. I have a big binder filled with those cards. I wish Nintendo would at least release the last of the Mario 3 cards, for those of us who still have e-Readers.
But yeah, I think the e-Reader is dead, at least here in America. The Japanese releases of Pikmin 2 and F-Zero GP both had e-Reader support, but were removed when brought to the US.
Strangely enough, I've heard about people playing Pokemon FireRed/LeafGreen and finding e-Reader prompts on the new island chain...