To be honest I don't think Billy will be around for long. I think Vickie will divorce him eventually(probably sooner than later) and he will become just a back burner figure again. Since they are bringing on CM to replace CW as Kelly and it is rumored that Jack and she will be paired, poor Billy will leave town with a broken heart maybe to return some day again or not.
I say this as I don't see anybody for Billy to be paired with after Vickie and also because I don't remember seeing anything at all about DT being on contract, just that he was coming back to take over the role of Billy once again.
Billy has become a useless character once again.