Recently, I have to configure UAG as Reverse Proxy for Lync 2010 deployment and had lot of issue getting it work and there was not a great deal of help on internet.
Finally, I got it working and i thought i should put up blog to save troubles for all of you.
Step 1 : Go through the Wizard ( UAG SP1 update 1) to publish Lync Web Services.
Make sure that HTTPS trunk is provisioned with a certificate containing all the public host names.
Step 2: Publish your Lyncdiscover service ( for mobility )
From the portal site click on "Add" on Applications,
Step 3 : Change Trunk Settings