Trend explanations are now provided by WhatTheTrend.com.

This is definitely helpful to the average Twitter user as it is typically very difficult to understand what some trending topics mean without pouring over search results (which may not be that hard, but it does take time). WhatTheTrend works by letting anyone help explain what a trend is via their website. The beta version of their site makes it quite easy to find new trends and add your own explanation.

I’m not clear on how the site handles abuse (i.e. people maliciously changing explanations of trends). However, each trend has it’s own feed of changes–which is a rather interesting feature. Another reason to use the site is that each trend is attributed to the person who started it. That feature alone makes the site worth a look.