Abilities become upgrades and while the damage per second of some units remain the same, they alter the damage and rate of fire so that relations between some units changes. Read all about it in the link below.

- Patch Notes – Beta Patch 11 –

Blizzard also made a write-up on why they did the changes, it’s quite the interesting read, check it out if you want to understand the reasons for the changes.

- StarCraft II Situation Report: Patch 11 –