Did playing Hearthstone during the beta grant any benefits that can't be matched by playing the game later?

There are a few pieces of exclusive content thusfar in Hearthstone. The first is a golden 'Gelbin Mekkatorque' card, that could be earned by using real money to make a purchase in Hearthstone while it was in the beta.

The golden version of this card is no longer obtainable. It was previously obtained by spending real money in the store during the game's beta test, prior to the full release of the game.

In addition, golden 'Elite Tauren Chieftain' was only earnable through purchasing a ticket to Blizzcon 2013, and thus also can't be earned any longer.

However, the normal version of each of these cards are still both able to be earned through crafting them.

Card backs will likely be exclusive to each season and event, such as the ones earned through levels in ranked on specific seasons, but thusfar, I haven't seen anything specific about this yet.

The only thing from the beta that can't be acquired anymore is the golden version of Gelbin Mekkatorque (for buying something with real money during the beta). The normal version of this card can still be crafted.

Also there is Elite Tauren Chieftain of which the golden version can't be acquired any more. That was granted by buying a Blizzcon 2013 ticket.