It's easy enough to sort by create_ts; updated again! The most recent thread for google.com is still pretty old. I'm kind of surprised that these multiple threads don't get automerged when the second and following people try to resubmit.
For instance, this article shows the more recent thread with little/no comments, while there's a great set of comments I'd prefer to see listed with it: http://www.forbes.com/sites/morganhartley/2013/03/19/how-a-y...
Good comments: https://news.ycombinator.com/item?id=5402301
No Comments: https://news.ycombinator.com/item?id=5400599
Both stories submitted 4 days ago.
This use case seems more common than the google.com one. It's possible you'd want to treat bare domains differently, or treat top web sites differently, etc. Depends on how much work you'd like to put into this project. I for one will keep using it if you keep working on it :)