Despite missing the playoffs for the first time in six seasons last year, Brumbies have handed Dan McKellar an extension.
Former Brumbies captain Sam Carter says the opportunity to join Ulster was "too good to turn down".
Allan Alaalatoa believes Australia can become a force again after signing a new deal until the 2023 Rugby World Cup.
James Slipper will attempt to rebuild his career with the Brumbies after serving a ban for cocaine use.
David Pocock has been preferred to Michael Hooper in the first Australian Conference players' team of the year in Super Rugby.
After 154 appearances for the Brumbies and 72 for Australia, Ben Alexander retired on Monday.
The Rebels fell short in a pulsating encounter with the Highlanders and need a favour from the Jaguares to seal a place in the last eight.
The Waratahs will play post-season Super Rugby thanks to their latest big win, while Ngani Laumape scored four tries for the Hurricanes.
The New Zealand Conference remains tight in Super Rugby after the Chiefs caught the eye with a big away win.
The Brumbies secured an important bonus-point win against the Sunwolves on Sunday, ensuring they remain in the post-season hunt.