In Champions lore, the forces of VIPER were a thorn in the side of mere mortals and law enforcement types, but were something of a laughing stock when matched against super humans and super heroes. Cryptic looks to change all that with the update, and the announcement features a lengthy listing of changes intermingled with some story-based explanations.
"VIPER forces throughout the game will change. We hope they'll be more interesting and fun to play, and not be quite the pushovers they are right now. You'll see these guys on PTS after the April Update goes Live. Let us know what you think," says Cryptic's Balserath in a post on the official forums.