Just my personal opinion, but I think it would be EXTREMELY stupid of Honda and RC to switch rides if he's still perfect after Millville. To be #1 for 12 events, 24 consecutive motos would be an outstanding record to own. I'm not an RC fan by any means, but I think he's got to go for this record. It's too much of a risk to switch bikes when everything is going so PERFECT for him.
Now, if he doesn't maintain the "perfect" streak, that's ok too. He's had an outstanding year already and you sure have to respect him for what he's done. In this case, I'd rather see him step down and ride a CR125 and race with Bubba. I think we'd really have some good racing there. The 450 will be there next year. It would be cool to see him ride it. However, in my opinion, if he's going to ride the 450, he should ride it for both SX and MX.
Just my thoughts.