That's the danger (or advantage, depending on your point of view) of web sites - they can be changed at will, and there's really no record. Except, of course, for diligent souls like us - who document such issues.
I have my confirmation email which states all three rebates, and I printed them out for the website before I ordered. If they decide to deny me the rebate, I suppose I can just take the drive back to CC in two months. They can either make me whole with the $60, or they can have the drive back and give me a refund.
That's the beauty of credit cards - if your sold a product which isn't as advertised, and you make a good faith effort to remedy the situation and offer the merchant the opportunity to fix the error, you can contest the charge and will (almost) always win. Even if you've already paid the charge off, it doesn't matter - you can still contest the charge.
Also, for those of you who don't believe that a store or manufacturer would sell a $160 item for $10...fear not - they aren't. Either here or at FW someone once posted a link to a rebate return matrix from (shudder) TCA. Even for large rebates, the return rate tended to be below 60%. For those similar to the $10 CC rebate, the percentage was down around 20% IIRC. I believe rebates for $100 or more had redemptions above 70%. Someone will certainly find the link just to check my numbers, and I'll be wrong on the details, but correct on the overall point. I'm sure they didn't really think about the consequences of $150 in rebates, but the law of averages says they'll only have to pay about half of the money out anyway. That puts the total at $85 on a drive which can be bought OEM for $107 or less on the 'net. Probably not a true loss, and even if it is it got a bunch of folks into CC today.