Today The United States Patent and Trademark Office (USPTO) amended their reasoning behind their denial of Sony's "Let's Play" trademark application. Previously the reason given for denial was "likelihood of confusion" because Let'z Play of America, a Georgia-based company, has had a trademark on "Let'z Play" since 2013. So the USPTO cited possible confusion with thier existing trademark as their reasoning for denying Sony's trademark application. The new letter also had attachments that showed the evidence that the USPTO used in making its decision. These attachments include: the Wikipedia article on "Let's Play", and the Reddit r/letsplay.
Denials can be appealed and Sony may have been preparing to, but today the USPTO released the amended denial of Sony's application before they could appeal. Sony can still appeal this denial as well, but since the reason has changed from "likelihood of confusion" to "merely descriptive" they will probably need to adjust their appeal. The "merely descriptive" means that the term that you want trademarked is basically just a description of what your good or service is or provides, instead of being a unique characteristic of your product. As the USPTO puts it, "A mark is merely descriptive if it describes an ingredient, quality, characteristic, function, feature, purpose, or use of an applicant’s goods and/or services." So because "let's play" merely describes what type of video you are creating it is not a trademark-able word. The point of a trademark is to help consumers avoid confusion; they are used so you can easily tell by looking at the trademark what company the goods or services are coming from.
Similar cases of companies trying to trademark descriptive words have come up in the past such as when the Sunbeam Corporation tried to file a trademark on the word "lektronic". The application was denied for the same reasoning as "let's play"; the word "lektronic" is basically just the word "electronic" which is merely descriptive so they were denied. We can only wait and see if Sony will appeal the decision and whether or not they will be denied again.
Okay Sony knock it off, you've been denied once, and now they updated your denial to solidify that you aren't going to get "Let's Play" trademarked. Hopefully this amended denial is enough to dissuade them from trying again, and to keep anyone else from applying for trademarks on commonly used words in the future, but let's face it, it probably won't.