ArenaNet have released a development update that sheds light on what they've been working on recently. It covers the new Engineer toolkit system and the redesign of Ranger pets, as well as a whole load of information about the cross profession combo mechanics which have been significantly fleshed out since they were mentioned previously. From the article:
In the past, we’ve talked about one of the more explicit ways in which Guild Wars 2 characters can interact: cross-profession combos. This system has been in development for some time. We knew it had a lot of potential, but we also knew we couldn’t flesh it out until more of the game was developed. Now that seven of our eight professions have been revealed (and the last one is undergoing testing), we have started to flesh out this system and create the building blocks that make it work. Cross-profession combo is the term we use, but these combos can also be created by two of the same profession and, in many cases, by a single character.
You can join the rest of the GuildWars 2 community to chat about what this update means for the game and keep up with all the latest news and discussion on our Guild Wars 2 Guru!