Welcome to Lucid Lynx Alpha 3, which will in time become Ubuntu 10.04 LTS.
Pre-releases of Lucid are *not* encouraged for anyone needing a stable system or anyone who is not comfortable running into occasional, even frequent breakage. They are, however, recommended for Ubuntu developers and those who want to help in testing, reporting, and fixing bugs.
Alpha 3 is the third in a series of milestone CD images that will be released throughout the Lucid development cycle. The Alpha images are known to be reasonably free of showstopper CD build or installer bugs, while representing a very recent snapshot of Lucid. You can download it here: http://cdimage.ubuntu.com/releases/lucid/alpha-3/
(Ubuntu Server for UEC and EC2) http://cdimage.ubuntu.com/kubuntu/releases/lucid/alpha-3/
for a list of mirrors.
Alpha 3 includes a number of software updates that are ready for wider testing. Please refer to http://www.ubuntu.com/testing/lucid/alpha3
for information on changes in Ubuntu.
NOTE: if you installed Lucid prior to Alpha 3, you may have libmysqlclient16 7.0.9-1 installed. This package was present in the Ubuntu archive by mistake and was retracted, but because it has a later version number than the real libmysqlclient16 package, the real package will not be installed automatically on upgrade. To ensure that you have the official package installed on your Lucid system and will receive security support for it throughout Ubuntu 10.04 LTS, please run:
sudo apt-get install libmysqlclient16/lucid
and follow the instructions.
This is quite an early set of images, so you should expect some bugs. For a list of known bugs (that you don't need to report if you encounter), please see: http://www.ubuntu.com/testing/lucid/alpha3
If you're interested in following the changes as we further develop Lucid, have a look at the lucid-changes mailing list: http://lists.ubuntu.com/mailman/listinfo/lucid-changes