Carlos Botero

Indeed, this feature is very useful, either the "merge topics" or the "Mark as duplicate" that Jake suggested

Btw, you could use it yourself for this case for instance ;-) http://screencast.com/t/oTbv9iS3x  and ar 2 votes to this threat from that one, hehe.

 

I would go for "Mark as duplicate" and perhaps would keep the topics separated so comments make sense as Jake mentioned. I would just add "automagically" any vote on the duplicate to the original topic.