Android SDK 1.6 is just released and available to be download.
The procedure to Install Android SDK 1.6 on Eclipse 3.5 Galileo is same as previouse version.
If you have installed Android SDK 1.5 with Eclipse already, here is the procedure to upgrade from Android 1.5 to 1.6.
Download Android 1.6 SDK, Release 1 -
from http://developer.android.com/sdk/1.6_r1/index.html, extract to any location you want.
Update your path if the SDK location changed.
Update Eclipse ADT Plugin -
Start Eclipse, Click Help >> Check For Updates.
Enable Android DDMS and Android Development Tools, click Next, then Next again to confirm.
Accept the Terms and click Finish.
And wait for Update finished, and restart Eclipse.
Update your Eclipse SDK Preferences (If your Android SDK 1.6 location changed) -
In Eclipse, ckeck Windows >> preference
Highlight Android, and Browse to the location of your SDK. Click Apply, and wait for a moment, the list of SDK will be displayed, click OK.
Create a new AVD for Android 1.6 if you want -
In Eclipse, click Window >> Android SDK and AVD Manager
Click New, Enter Name and select Target..., Create AVD.
After upgraded, you have to set your Build Path again as described in Install Android SDK on Eclipse 3.5 Galileo.
Right click you project, Build Path>>Configure Build Path...
Enable Android 1.x and click OK.