The new alpha of LinuxMCE 0810 was released yesterday. The third one. The installation procedure is not changed. You still should have the Kubuntu 8.10 installed on your PC. Then alpha2 installer will download and install LinuxMCE 0810. Just follow that simple instructions.
According to 0810 alpha wiki page a lot of bugs was fixed since alpha 1 and 2. So, if you’d like participate to LinuxMCE by fixing bugs or just submitting bugreports fell free to install Alpha3. But note that this is still alpha version and it can be unstable. So, do not use it in production systems!