How do I get a Joomla! 3.x template?
Some template companies will be offering Joomla 3 templates either right away or shortly after release, but you will need to ask each one. Some have already announced that their templates will be ready for Joomla 3 when it is released, but others have not. Also, please note that some Joomla 2.5 templates will work in Joomla 3 without any issues or any changes needed. It's best to consult with the developers on this.