ECLIPSE: can't download new software, stays stuck in 'pending...'

Go to "Preferences"->"Install/Update"->"Available Software Sites" and uncheck all except "Indigo". Then try again. I think eclipse gets updates from all sites before it gets through "Pending..."-stage.

Then re-check items until you find the one that causes it to jam.

Check if there is proxy server configuration that prevent the direct access. you can define it in the preferences.see more details here.

In my case I use proxy setting, and I follow the answer provided by oshai, and it works. But just one small modification for the post: the SOCKETS setting should be clear and empty as suggested by here