No thank you. There's already enough for moderators to do on the sites.
There have been a lot of requests for this on Meta Stack Overflow (now Meta Stack Exchange), for example 50 reputation for making comments is too high and Lower the amount of reputation needed to comment among many others, and the consensus is that it's hard enough to police posts for spam, etc. on most sites, and this would add a lot of work, as mentioned above. In addition, implementing such a feature would likely require a change in the codebase that handle comments and wouldn't be customized on a per-site basis. Our load isn't unbearable here on Chemistry, but standardizing such a feature across all of the Beta sites would force mods on sites with much more traffic to deal with the comments as well.
Fear not, though. If you see a comment as an answer on here that's worth salvaging, go ahead and flag it using the "Other" flag option, and we'll make a decision what to do with it. Honestly, though, the answer/potential comment in question doesn't really add any valuable information since the other answer covers the matter so extensively.