Anona?

I will land as a Canadian Permanent REsident at Windsor, Ontario on May
2007 (to live in London, Ontario). I am currently in the US on F1 visa
(changed status in US from tourist to F1). However, I will go to China
to settle other things (June 2007 or as soon as I have my PR Card) and
will go back to London, Ontario on July 2007 for good.

My tourist visa is still valid until 2010. I will fly from Detroit to
China and back from China to Detroit (does this make any sense...?).
Coming back from China, I don't have a return ticket after Detroit Intl
Airport because I'm thinking of just driving to London (mapquest says "2
1/2 hours").

Will that be a problem if I will tell US Immigration officers in Detroit
that I will just drive from the Detroit airport to London?

Any thoughts please?