Worms is a good series but I think it's incredibly hard to innovate in this series, they've really done it all with Worms Open Warfare 2 IMHO, that was a great game with lots of fun modes, things that were a bit different from the usual gameplay.
My idea is kinda making it like all those "smartphone games" like Words with Friends and stuff. Basically each player does a turn, and when they finish, that turn is sent to the opposing player. Then, whenever they have the time, they go to their turn, do it, and then send it back. Considering it's turn based strategy and turn usually take under a minute, it seems ideal for 3G gaming and it would really help legitimize it as well.
C'MON TEAM17, YOU OWE ME ONE.