The checkout enhancements module provides a few tweaks to the checkout pages that I wasn't quite ready to drop into core so late in the 1.0 development cycle. These features are up for testing and feedback, and the enhancements as they are or modified versions may find themselves part of core in the future.

Currently included enhancements

• Removes the cancel button from the checkout form.
• Adds a throbber and disables the 'Submit Order' button to prevent multiple clicks.

There's a simple menu to toggle enhancements on or off at:
Administer > Store administration > Settings > Checkout enhancements.

Let me know how it drives!