Atheist "megachurches"?

I'm not sure that the attendance of 400 cited in this article qualifies as a megachurch but perhaps in comparison to HSGP, it is.  

http://www.usatoday.com/story/news/nation/2013/11/10/atheist-mega-churches/3489967/

Do we need to have sermons, inspirational music, quiet reflection at HSGP Sundays?  My guess is that the answer is NO.  We might think, however, about whether HSGP could attract more attendance with changes that are acceptable to us all.