Joe,
In Pick the Piece Big Chess, I started out with this premise. And taking it one step forward - Chess players will probably like a 'natural' start position, not one with the pieces in the middle of the board.
Thus you have two empty slots in the wings after you fill in the holes with pawns.
Further design considerations: Bigger board weakens the knights and the pawns. Stepping knights seem an interesting solution.
Dropping extra pawns (stronger pawns) help with the pawns as well.
Net result - similar to chess but still different.
The lesson from 80 square chess variants applies - change one parameter and the game is radically different.
The only possible 'next' chess is something like Fischer Random or perhaps just an alternate setup - something like Displacement Chess, and even these are doubtful - we are talking the next 100+ years or so.
Trying to 'convert' chess players to this new variant reminds me of Communism -- it will only work under a dictatorship in the end ...LOL.
I mean, come on, we will all be long dead before Chess 'dies' - lets not get too obsessed with the 'next' chess since there is a good chance that this next chess never happens!