Trends happen with anything creative. Since digital photography is very popular, it is easier than ever before to share photos which means more people are exposed to these trends in photography. Photos are timeless, they can be relevant for decades. If you want to have classic wedding images here are some things to aboid because they create a "time-stamp" on your pictures (things other than hairstyles & clothing).
- Lens flare (think J.J. Abrams)
- Vintage look (undersaturated, color filters)
- Selective color (black and white photos with one splash of color for something like flowers)
- High contrast (or poorly done HDR)
- Textures (the sky never looked like it had scratches, so why does it look that way in your photos)
Some of these trends might be really awesome right now, but 10 years from now it will be down right cheesy. Remember your parents' wedding pictures? No, let me remind you:
Lets not forget the classic photo of the couple in the wine glass.
Not to say you should completely avoid trends, but since wedding pictures are valid longer than your senior pictures (please take those ten-year-old photos off the wall, Mom), having timeless images is going to be just as important as having beautiful images.
Photographers: Again, I'm definitely not saying to stay away from trends, but the key is to focus your sessions on great pictures, with great lighting, straight out of the camera. Don't depend on trends to make your finished product look good.