The Fantastic Four are generally known for getting their powers when they venture in to space to study a cosmic storm from afar. A miscalculation on the part of Reed Richards meant that they actually weren't as far from the storm as he thought and exposure to it altered their molecular structure, granting them their respective abilities. In this movie, it has been said that they will gain powers when Reed Richards looks in to opening portals to and venturing in to alternate dimensions. One on occasion, they Fantastic Four will step in to one of these dimensions and come back having gained superpowers in there. It's a controversial change (and one ripped directly from the recent Ultimate universe, for the record), but one that will at least differentiate it from the origin stories of the last Fantastic Four franchise. How it will go down with fans remains to be seen - though the fact that the whole "other dimension" thing means alternate universes could be explored in this continuity is exciting.
