I've seen some previews, and they will have some very promising dresses. There's also Loriann, another Montreal company, who make some very nice dresses. Those two should set you well on your way. There are no really latest fashion trends for hairstyles because so much depends on the type of dress you wear, the type and length of hair you have, and on the shape of your face. Whether you wear the hair up or down depends on the effect you want to have on those around you.
Hair up is the most formal and elegant way to go.
This way, the movement of your skirt will be complemented by the movement of your hair and you will be perfectly in balance. First, your dress. Of course you can wear just about anything you want, and ballgown style dresses are really popular this year. As for sleeves and necklines, sleeveless is sexier and more formal, also less bridesmaidsy. And if it's sleeveless, spaghetti strapped or low cut, then you can also wear your hair down.