Blizzard posted information about changes coming to WoW Tokens soon (already rolled out in the US):
The goblins of the Bilgewater Cartel have a golden opportunity for you, friend—introducing a new way to use your WoW® Token. It’s just as easy as ever, but now when you use gold to buy a WoW Token from the Auction House in certain regions, you can then choose whether to convert it into 30 days of game time or Battle.net Balance*. You can use Battle.net Balance to buy services like World of Warcraft character transfers, digital products like pets and mounts, and even purchase in-game items for other supported Blizzard games you play.
Please note: this new feature is available now in the Americas game region, and will be rolled out to players on European servers soon.
Buying a Token is simple: just visit the Auction House and use your hard-earned gold to purchase one of the WoW Tokens put up for sale. Once the Token arrives in your in-game mailbox, right-click it to add it to your bag, then right-click it in your inventory. You’ll then be able to choose whether to add 30 days of game time or add Battle.net Balance (12.99 EUR / 9.99 GBP; currency and amount varies by region) to your Battle.net account.
For more information, check out our Battle.net Balance support page and WoW Token support page.
*WoW Tokens can only be redeemed for Battle.net Balance in the currency associated with the registered Battle.net account address. Other restrictions apply.