BlackBerry maker RIM is opposing Apple's trademark filing for WebKit, the open source browser rendering engine they developer based on Linux Konquerer/KHTML. WebKit has become the most popular browser engine in Mobile, powering iPhone, iPod touch, and iPad Safari, as well as BlackBerry's Torch Mobile, Google's Android, Palm's webOS, and other browsers -- as well as Apple Safari and Google Chrome on PCs. So popular, in fact, that RIM couldn't wait to advertise they'd finally joined the modern internet by getting a WebKit browser.
Could that be part of the reason for the opposition, fears that Apple would try to restrict use of the trademark? Even CrackBerry.com doesn't seem to know for sure.