In short, now when you go to the Google Trends home page you will see "hot trends" under the search box. These hot trends are made up of USA based queries. What makes a query hot? If there is a sudden increase in searches for that phrase, something out of the norm relative to the historical look at that phrase, it will be considered a hot trend. I gave several examples in my article at Search Engine Land.
Let me give you one more that is related to why Tamar and I will be out Wednesday and Thursday. The Jewish holiday of Shavuot is tomorrow, we won't be here, so expect some prewritten articles and articles from the other authors. But since Shavuot is a seasonal event, typically, throughout the year, no one searches on that term. But now that Shavuot is tomorrow, there is a spike in people searching for it.
Right now, Shavuot is 36 on hot trends list for me. Here is a link to the trend for May 22nd for Shavuot.
As you can see at the top right it shows the date, which you can change. Then it shows the "hotness" level, in this case, it is only mild. It shows the search volume throughout the day. The search query "peaked" 22 hours ago, meaning Google noticed a spike in people searching for that search term 22 hours ago. What I find very interesting is that the "location " is 9% New York - well there a lot of religious Jewish people in New York, so that may make sense. Then at the bottom you see news articles and blog posts, followed by related web pages. I suspect news and blog posts have a lot to do with the hot trends reports.
Now, just think how this can be useful for SEOs. Hot trends. Hmm...