Guild Wars 2 is planning a major profession balance overhaul in the June 28th update. Some of the notes in the balance section were shared with the community and the list of changes to skills is extensive. Changes to the Rune of Sanctuary and some general changes were also revealed.
When it comes to professions, there will be changes across most, and some of these changes affect just PvP or WvW, some effect PvE only or PvP only, so it will be a good idea to read through all of the notes that affect your classes or advanced classes carefully. For example the Catalyst gets changes where damage reduction applies in PvE only, while the Strength in Numbers trait for the Guardian under Valor has been reworked to grant protection to allies while in combat. It will now apply protection with a three-second duration and a ten-second interval.
There are so many changes, though some in the community were quick to respond to the Warrior changes in particular. Things like how Charge for Warhorn will no longer grant allies increased damage, but instead they get quickness and the cooldowns have been increased. Banners also no longer give attribute bonuses to your allies, instead giving them quickness.
The Rune of Sanctuary will now also convert healing received from healing over time effects into a barrier while in combat, but at a reduced rate of 10%.
Although some of the changes do things like reduce cooldowns or increase critical chance, depending on the class, there's too much to sum up, but if you are a Guild Wars 2 player, it's very likely there's something new that you will have to get used to.