STYLETHREAD -- LET'S TALK SHOP!

I keep hearing that Northwest Airlines may strike in the next few days.  This is a stupid question but what happens if you are schedule to fly them and they strike?  Do they just cancel it and give your money back and then you are on your own?  Do they accomodate you on a different airline? 

I am flying to Las Vegas in a couple of weeks and I am starting to worry.  On top of this, we booked our flight on Expedia and I'm not sure how that is handled either.

Anyone know how this works?