Think of it this way -- Whole-Brain Teaching is a method of running your classroom, and of delivering quality instruction, and having lots of fun. It's not something that gets 'old' because it's not presented as being a 'novel' thing in itself once you've done it a while...it becomes a part of your classroom community -- even a 'language' and a way of operating. Certain games could 'get old'... and at times your students may become 'lax' because it IS so natural, but then you change up little tiny things, and you up your own energy level for them to feed off. Just like before you discovered WBT...you teach and run your class pretty much the same way every day, and that's the background stuff that doesn't 'get old'...it just.. works! Then, you change up the little things in various activities, games, lessons, visuals, whatever....
Feel free to ask us for suggestions, tips, etc... we're always here, and we all have been through the first few years which are the most work.