I've only taken a cursory glance, but from what I can tell, twitchy is a twitter aggregation site. I think that's pretty brilliant, when so often now tweets are an integral part of a news story.
If you think about how something becomes newsworthy when it explodes on twitter, and take into account the chaotic format of twitter, it makes sense to have a place dedicated to following trends and aggregating those trends into a non-twitter-like format that is easier to read.
And how often now does someone tweet something and then scurry to remove it or delete their account?
Not anymore.