Deal is still on, at least at B&M. I walked in yesterday and they had the "old" sign up. The coupon code on the advertisement for the 100 instant rebate still worked and she typed it in no problem. I showed her a couple of pricematch printouts showing the monitor in stock and that it was the same new retail item. I somehow "forgot" to print out a page showing how much shipping costs. Per Staples policy, she tried to add $5 shipping and handling for unknown shipping costs, but for some reason it didn't seem to take. I asked if I could use another coupon but she said I couldn't. I probably could have pressed the issue but she had mentioned all the people "abusing" the deals so I let it slide. Besides, the fine print on my printable coupon says you can't use it in this case anyways.
Final cost: 349.98 - 100 (IR) - 27.48 (PM) + 12.75 (Tax) - 150 (MIR) = 85.29
Entering in the S/N on Compaq's website confirms that MIR is good.
Just be extremely nice when trying to work the deal B&M and you'll have a much easier time, IMNSHO.