Looks like there is some progress on an 8.4 jailbreak. Hopefully this will be released fairly soon since I will be giving up my jailbreak on my iPhone when I get my watch on Friday.
http://www.redmondpie.com/ios-8.4-jailbreak-demoed-on-video/
http://www.redmondpie.com/ios-8.4-jailbreak-demoed-on-video/