Currently, users can't unlock the Android software on the Motorola Atrix, but after the protests from Android fans in Australia, it may change and have a bootloader similar to the one on the Motorola Xoom.
Motorola reported on its Facebook page that they would be working on a bootloader solution that would support developers while protecting end users. Irwin Proud from Melbourne, Australia, bought a Motorola Atrix while in the United States because he wanted the dual-core processor speed and couldn't get it unlocked. After emails and letters, he started a petition with 8,500 signatures, and Motorola finally responded.Motorola contends that it is working on a bootloader solution similar to the one on the Motorola Xoom as long as the carriers agree.
Here's a copy of Motorola's response:
"In terms of your question - we completely understand the operator requirement for security to the end user, and as well, want to support the developer communities desire to use these products as a development platform. It is our intention to enable the unlockable/relockable bootloader currently found on Motorola XOOM across our portfolio of devices starting in late 2011, where carriers and operators will allow it."