First install the relaunch and mce7 tools. Within relaunch you can add direct links to websites. I set it up to open fullscreen in chrome and control it with either a keyboard or my Harmony One (using assassins harmony mouse trick). With relaunch you can set it to 'close" so that after you close the website WMC will open backup. Similar to hulu desktop. Further with relaunch203 you can add images etc.
With MCE7 reset (similar to MCStudio except it still works) you can edit your WMC start menu. So below is a crappy iphone pick of my "streaming" section. Where I have local streamers like netflix, hulu desktop and also have websites that open (HBOGO, xfinity On demand, mlb.tv etc) .Lastly I moved the kylo website to the end of streamers as well to ad a few more options.
I also have an alt+f4 button programed to my harmony one so it is easy to get back to WMC for me.