If they still consider the America a Bonneville class motorcycle then I would think they would have to move it up to the 1200 cc. If they can keep it in the same weight class then it will be their entry level cruiser. (Entry level is a term I do not like, but that is a later conversation)
The newer Americas are more refined and have a Thunderbird LT lite look to them, so if the weight goes up much there is not need to keep the America in the lineup.
I agree with Dog. If they would give the America and Speedmaster a different stance like the older models it would be great for the lineup.
I am perfectly happy with my current bike so it makes little difference to me, but it will be interesting to see what they do.