Your Fallen Earth account wont just roll over automagically. Players will need to make a G1 account and then merge their Fallen Earth account with that one when the move is complete. Once this is done, youll be able to log into your G1 account and keep playing Fallen Earth using all of your usual account goodies and characters.
The process will be available starting on August 1st, but current subscribers that complete their merge before August 5th will be eligible for some free G1 Credits as GamersFirsts way of saying thank you for completing the transition.
There are also some changes that some players will need to be aware of if they intend to continue subscribing to the game. Credit card payers will not have to do anything as the billing will continue to recur as normal, but if you're using PayPal or Click&Buy, youll need to set the subscription up again once the transition completes since these will not automatically renew.
Source: Fallen Earth Dev Blog