If the Consistory were held today, Benedict could name 13 new cardinal electors; if he waits till the end of August he could name 14, and if he goes into October he could appoint 17, maybe 18. That would be a sizeable class, and some significant reshaping could be accomplished by naming so many new cardinals at one time.
An interesting breakdown at that link.
There are a lot of people who could become a cardinal, but there are not enough red hats to go around and only a fraction of them will be Americans. However, I think its safe to wager that after the next consistory Archbishop Burke will be Cardinal Burke.