I recently came across this issue after applying some scalability settings, and couldn’t initially figure out why the publishing was no longer working.  Accessing the Desktop and using site publishing would display the dialog, but would hang on the Initializing… stage.  After some preliminary investigation, it turned out that the issue was with the instance names provided in the scalability settings.

Initial Investigation

Some investigation on the web turned up a few possible solutions, but they didn’t work for me.  In case these might be helpful for your scenario, here they are:

• Is your Sitecore publishing stucks (sic): A lot of possible debugging options and detailed analysis
• Sitecore Hangs on Publishing : Blog post suggesting an IIS reset.
• Sitecore publishing initializing: Suggests a possible upgrade error to 6.3 where the event queue table is not correct.

Scalability Settings Problem

In my particular case, this was not the root cause of the issue.  After examining my changes to the scalability settings, I noticed I had incorrectly set the local instance name on the authoring server.  Both my content delivery and authoring servers had the same instance configurations:

<?xml version="1.0"?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
   <sitecore>
      <settings>
         <!-- INSTANCE NAME
            Unique name for Sitecore instance.
            Default value: (machine name and IIS site name)
         -->
         <setting name="InstanceName">
            <patch:attribute name="value">MySite1</patch:attribute>
         </setting>
         <!-- PUBLISHING INSTANCE
            Assigns the instance name of dedicated Sitecore installation for publishing operations.
            When empty, all publishing operations are performed on the local installation of Sitecore.
            Default vaue: (empty)
         -->
         <setting name="Publishing.PublishingInstance">
           <patch:attribute name="value">MyAuthoringSite1</patch:attribute>
         </setting>
      </settings>
   </sitecore>
</configuration>

The solution

The quick fix was to make sure the InstanceName value set on the publishing instance configuration matched to the Publishing.PublishingInstance value.  This resolved the publishing issue and no longer caused the dialog to hang on the Initializing state:

<?xml version="1.0"?>
<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
   <sitecore>
      <settings>
         <!-- INSTANCE NAME
            Unique name for Sitecore instance.
            Default value: (machine name and IIS site name)
         -->
         <setting name="InstanceName">
            <patch:attribute name="value">MyAuthoringSite1</patch:attribute>
         </setting>
         <!-- PUBLISHING INSTANCE
            Assigns the instance name of dedicated Sitecore installation for publishing operations.
            When empty, all publishing operations are performed on the local installation of Sitecore.
            Default vaue: (empty)
         -->
         <setting name="Publishing.PublishingInstance">
           <patch:attribute name="value">MyAuthoringSite1</patch:attribute>
         </setting>
      </settings>
   </sitecore>
</configuration>