I'd be bummed to see them gone if they really are gone. The set has been around in some fashion since 1998, back when we still had Topps, Bowman, Fleer, Donruss, Leaf, Score, Upper Deck, and Pinnacle brands in the baseball market.
I like the irony of the fact that Opening Day cards started out as the flagship cards with an extra foil logo and somehow ended up as the flagship cards with the removal of all foil. It's a weird, quirky set. Last year, it featured some designs from Series 2 flagship cards that we wouldn't see anywhere else until months later.
I''ve *almost* completed my sub-collection of every Orioles Opening Day card...
RIP (?) Topps Opening Day! Somewhere, you're hanging out with Topps Big League and Topps Stickers.