Probably a bit late, but steak is fine to cook well past the dates they show (obviously i mean like 1 or 2 days). As long as you heat the steak all the way through and the juices run nice and clear, then you're fine (sorry boys, no bleu steaks for you!).
The dates they put on steaks, like all food, is to cover their own arse. They stick an early date on and people use food quicker, thus buy more quicker. Also if someone was to get sick for whatever reason, the company can say "well we put a date on there for x days ago so its your own fault" and thus cant be blamed. It's just an insurance thing.
Trust me, i'm a chef*!
*Not actually true. I was a chef for 7 years. Not anymore.