Magmic had some holiday spirit remaining and decided to make their Cosmos BlackBerry 7 compatible theme (also including earlier devices) free for a limited time. That means you can test out a solid premium theme on your BlackBerry 7 device for free! They are not saying how long the free price will stay but they want to know what you think! So far the only BlackBerry 7 devices it supports are the Bold 9900/9930 and Curve 9350/9360/9370/9380. Hopefully more are coming!
Pick up Cosmos free in App World at this link. It is available for most OS 4.2.1+ devices.