Yes your ether is good on both chains until block number 1920000. then the winning branch will take over completely and exchanges and miners will continue to operate on the new branch as if nothing happened.

Technically both will run side-by-side, but doing any transactions beyond block #1920000 on the losing chain will be disqualified.

In either case nothing will happen to your ether, and there will most likely be an instant replacement for the wallet application once block #1920000 is hit. or simply selecting the winning chain in the client should move you over on the new chain