Is this dress too informal for a wedding dress?

I'm having a very informal wedding in New Mexico. I'm not a girl that likes anything frilly, like lace or glitter. I thought about wearing this as my wedding dress. I also want my bridemaids to wear the same dress dyed light blue. The groom will have a white shirt with navy pants and tie. The groomsmen will be the same but with a light blue shirt. I tried on wedding dresses at David's Bridal but didn't find anything that I liked. That's when I found this dress at JC Penny. Here's the link http://www4.jcpenney.com/jcp/X6.aspx?DeptID=50434&CatID=56292&GrpTyp=PRD&ItemID=15ceb46&attrtype=&attrvalue=&CMID=50434%7C50444&Fltr=&Srt=&QL=F&IND=170&cmVirtualCat=&CmCatId=50434%7C50444%7C56292&mscssid=6b316701db0f441da94f1c47bb0acd271xMnVNoVza3WxMnVNoVza3o200BC0DC74F53A650D023F83D698260E34DA0916502&edmsid=9d1086668b4f4ea1b81144ae1a6302eb