I think Byrne broke his heel and will be out for a while, maybe the whole SX series.
Not too sure about the Stewart thing - I don't doubt he's injured that knee, but I think Reed has his measure this year. Chad is right on it and very confident while I think Stewart needs to get his head together. Or put another way, Stewart will have a tough job getting back to where he feels confident enough to keep a series together.
But it's a real shame, I'd really like to have seen them both fit for the series, it would have been a brilliant thing to see.
Chad's championship? I think so...