I'll probably be installing the SimpleComments MT plugin soon. Merging Trackbacks & comments seems sensible to me, although I'm slightly concerned about whether it plays nice with the MT-Blacklist plugin.
But I have to admit that what I really love most about Simple Comments is the authors' summary of the MIT License which goes like this:
Like our other freeware, this plugin is released under the open-source MIT License. In plain English, that means you can do whatever you want with the software, including modifying it, selling it, or eating it, but we’re not responsible for anything that goes wrong.