An Optus spokesperson told CNET Australia that Optus will be receiving the update in the "coming weeks" and will then perform tests to ensure optimal performance for customers who own an HTC Dream on the Optus network.
"HTC Dream owners on the Optus network will automatically receive the upgrade over the air once testing is completed," the spokesperson said.
Cupcake is the codename given to version 1.5 of the Android operating platform. Google has previously outlined some of the enhancements users can expect in the update including a video recording and improvements to the Gmail client on the phone.
The Boy Genius Report has published speculation that T-Mobile in the US will push the update over the air to its customers starting on the 11th of May.