Yahoo Mail will soon be getting a big refresh, according to a report from Kara Swisher, who has a strong track record of breaking Yahoo-related news and sharing leaked information from within the company.

Last week, Swisher shared some screenshots of a reportedly forthcoming Yahoo Homepage, which she says will roll out in December, and she’s now saying, citing sources close to the company, that a new “more Gmail-like” version of Yahoo Mail will also launch in December.

According to Swisher’s sources, CEO Marissa Mayer (a former Googler, of course) wants to better compete with Gmail, and feels Yahoo has been missing out on a major opportunity to do so.

According to recent data from comScore, Yahoo still leads over Gmail in the U.S., but Gmail has taken over to become the world’s most popular webmail offering. In fact, that data also had Yahoo trailing Microsoft’s Hotmail worldwide.

If the new Yahoo Mail is coming in December, I would imagine that we’ll be seeing some screen shots leaked fairly soon. It will be interesting to see how much resemblance there is to Gmail.

Of course, Gmail isn’t standing still. Google continues to push updates, such as the new compose and the addition of Gmail results to search results. Google is also continuing to integrate the Google+ social layer across its products with the aim of creating a more unified Google experience. Gmail is a major piece to this puzzle as Google+ grows its user base.