Interesting question to ask a friend. Why don't you google "2013 wedding cake trends"? Or better yet, she can meet with some bakers to see what designs they can offer her at what price point.
Tell her to just pick a design she likes. I will recommend buttercream over fondant though. I think fondant tastes like sugary glue while buttercream icing is glorious.
here you go:
Websites/blogs where our wedding has been featured: