Guild Wars 2 Microtransaction Developer Blog

In a new blog entry on the official Guild Wars 2 website, ArenaNet's Mike O'Brien discusses the team's philosophy on microtransactions before revealing that players can now buy gems from the in-game cash store which can ultimately be exchanged for gold. And yes, that means that ArenaNet is taking the same path as Blizzard in trying to eliminate gold sellers:
In Guild Wars 2 we have three currencies: gold, karma, and gems. Gold is the common in-game currency. Karma, which players earn in-game but cannot trade, is used for unique rewards. And gems are the currency that's bought and used to purchase microtransactions.

We have a new player-driven market that allows players to trade gold for gems and gems for gold. If you want something, whether it's an in-game item or a microtransaction, you ultimately have two ways to get it: you can play to earn gold or you can use money to buy gems. We think that's important, because it lets more players participate on a level playing field, whether they use their free time or their disposable income to do it.

MMO veterans will note the similarities of our system to EVE Online's PLEX system. As in that case, our system takes gold trading out of the hands of real-money trading (RMT) companies and puts it directly in the hands of players.

We think that's a great thing.

From a player's perspective, RMT companies have all the wrong motivations: the more money they make from selling gold, the more they spam ads in the game, run bot networks to farm gold, and hack accounts to loot them for gold. Conversely, under our system, players have all the right motivations. If a player buys gold from another player, he gets the gold he wants, the selling player gets gems she can use for microtransactions, and ArenaNet generates revenue from the sale of gems that we can use to keep supporting and updating the game. Everyone wins.

We also like the tradability of gems and gold because it makes the rest of the game's economy more compelling. We'll have a player-to-player Trading Post in the game it's like an auction house but better which we'll discuss in an upcoming blog post. Because gems can be traded for gold and vice versa, we don't need two different trading systems, one for gold and one for gems. In Guild Wars 2, everything on the Trading Post is traded for gold, but of course, somebody who wants to earn gems can just sell items for gold, and then convert the gold to gems.