Three words: Four. Way. Diff.
Show me where my patch (before and after) conflicted with the last patch (via blame) before and after. Bonus points if you can show both complete commit messages. Extra bonus points if you look at the branch, figure out where it went wrong (at what point did my patch last apply cleanly?) and show me all the commits since.
Telling me shit's fucked up doesn't help anyone (that's what I got with cvs).
Telling me what I was trying to do tells me what I was trying to do, not what Bob was doing when he checked in before me, but at least I know what the hell I was doing when I did it months/years ago (this is where I am now with git rebase).
Telling me what the hell I was trying to do and what the hell Bob was trying to do, now that's what I need, because now I know what it's supposed to be doing when I'm done merging the code and can do so with a reasonable degree of confidence that both Bob and I will be happy with the result.
For my company's workflow, this would be the holy grail of revision control. I'd even be tempted to use a graphical tool to do it.