The current trend of 3D animation movies started in 1995 with the first Toy story. Back then, the concept of a whole movie created entirely in 3D was new and revolutionary.
Today, every studio is releasing one (or several) 3D movie each years (and I'm not talking about 3D movies with glasses. Just a movie made with a 3D software).
I don't think that this trend will end pretty soon, but creating movies with such high standard might be a great challenge for the future. The studios will find it hard to create amazing movies like Ratatouille or the Incredibles on a yearly basis.
One day, movie lovers will get tired of this recipe and ask for something fresher or more original.
Many believe that 3D movies, the one with the glasses, will be the future. To make people go to theaters, you have to give them something original. Something that they can't get at home, even on a 50 inches flat screen TV.
Personaly, I'm not a big fan of 3D movies with special glasses. The concept is fun for 20 minutes or so. But after two hours, my head is really spinning too much!
Is it the new trend for movies? I think it is! Will it last for a long time? Probably as long as a new technology hasn't been found to replace it with something even more cooler!