How do you install new notification center apps into Yosemite? Will it not be available until the public release? I am really liking the new notification center with it's widgets/apps etc... On another note, why can't I use the voice texting in the notification center Messages, but I can on the Mac OS X Messages app? I would like to install MLB, ESPN, notifications in the notification area for example, during the playoffs! Will it be apps that have notification center options or separate widgets! Thanks!