Firstly a big thank you to everyone who helped with Moodle 2.1 QA testing. We managed to get through the complete cycle including retesting in just two weeks!
All our QA testers are listed in Testing credits and are included in the testers group here in Using Moodle.
Although our QA cycle has finished, we can continue testing Moodle 2.1 using moodle.org, which was recently upgraded to 2.1. Already a significant bug - Forum attachments no longer displayed MDL-28172 - has been reported and fixed. The fix will hopefully be included in 2.1 and applied to moodle.org next week after going through integration review and testing. Our other Moodle community sites such as http://school.demo.moodle.net are due to be upgraded to 2.1 soon.
As always, if you come across a problem, please check that it has been reported in the Moodle tracker.