After a first scan of the list: the winner is .APP, with 13 applications. The only obvious trademark conflict I saw involved .COACH (2 applications) and .MONSTER (2 applications). (UPDATE – Google filed by .ING, but ING didn’t. Also, .SAS filed for by two different applicants) Google and Amazon will butt heads over several generics. L’Oreal filed for .BEAUTY. There appear to be approximately 195 strings that have 2 or more applicants. Seven of these are in non-roman characters (the Han characters for INFO, ENTERTAINMENT, GUANGDONG, .WEBSITE, .NETADDRESS, .WEBSTORE and .WEIBO). The longest strings appear to be .TRAVELERSINSRUANCE and .NORTHWESTERNMUTUAL.
Here is a rough list of the most-filed for strings: