Blizzard may add microtransactions to Diablo 3 in some regions of the world - but there are no plans to include Europe or America yet.
"Some new features may start to show up in data-mined information for patch 2.2 that will not apply to all regions. Specifically, the following features will not apply to the European [or American] region:
- A new currency called Platinum
- Timed experience boosts
- New cosmetic items including wings, non-combat pets, and character portraits
- References to stash space and character slot expansions
- A new UI interface that references the above information
"We recognise that many players have expressed an interest in microtransactions being added to Diablo 3. While we may explore this model in some regions, we have no immediate plans to implement such purchases or the aforementioned features anytime soon for the Americas region."
Nowhere has Blizzard confirmed exactly which regions it "may explore" the microtransaction model for - apparently there's a post in the Korean D3 forum ruling that region out as well - but 'for the game's launch in China' is a strong bet.
Diablo 3 is officially on the way to China but awaits the government's approval. It could be weeks, it could be months.