Google have released version 2.0 of Android (codenamed "Eclair") to the public developer SDK. Rather than a separate download, if you are running version 1.6 of the SDK already, the 2.0 AVD image can be downloaded within the AVD Manager.

To run the AVD Manager on Mac OS Snow Leopard, you may have to edit the 'android' script file in the Tools directory to force the system to use the 32-bit Java VM rather than the default 64-bit one. Locate the section starting:

# Mac OS X needs an additional arg, or you get an "illegal thread" complaint.
if [ `uname` = "Darwin" ]; then
    os_opts="-XstartOnFirstThread"

And add -d32 so the section reads as follows:

# Mac OS X needs an additional arg, or you get an "illegal thread" complaint.
if [ `uname` = "Darwin" ]; then
    os_opts="-XstartOnFirstThread -d32"

Now open a Terminal window and run './android' in the Tools directory of the SDK (wherever you have saved it). The following window will be displayed:

Click on the Available Packages option, the following window will be dsiplayed:

Select the Android 2.0 API and click Install Selected:

Click Install Accepted.

Once downloaded and installed, return to the Virtual Devices view and select New:

Select 'Android 2.0' as the Target. Create the Virtual Device, then click Start to launch it: