Spotlight is broken on my main partition in OS X 10.7.4
I found this issue when searching for the web. Though it's been some time since the original asker has posted his question, I thought that it would be worth noting that, as of October, the Mac OS X 10.7.5 supplemental update resolved my Spotlight issues.

I was experiencing symptoms similar to the original poster's, with the same error messages that he encountered.