I have been using Eclipse happily for years, but lately it has been a nightmare for me to update anything, including PHP support and Android SDKs. Surely, I just changed my laptop from 32-bit XP to 64-bit Windows 7, but that should not be a problem to Eclipse and update servers.
The update process hangs up very early in the update process, for example at "Fetching children of Indigo: 13%" or "Fetching content.jar: 3%" and stays there forever (until timeout). I tried to change the update servers, tried to change the protocols and finally udpated the Eclipse version from Indigo to Juno. I also tried to run the Eclipse versions as an administrator, but the same freezing occurred.
As the same update problems were still occurring with Eclipse Juno, I came to conclusion that it is related to my computer and network setup.
After some thinking, I finally turned off my antivirus program (AVG) . After disabling the AVG temporarily, the Eclipse update feature started to work again!
So, if you are experiencing very slow response when trying to update Eclipse, try to turn down your antivirus software.