I just bought a Macbook Air 128GB-4GB-1.86GHz from macmall and got parallels and a printer. I sent in all the rebates and got a letter a couple of weeks later saying that one of my rebates had been denied. I called them up and after a 15 minute phone call (me on hold a lot of the time), the staff in broken english said that my rebate would in fact be issued. My other three rebates were explained to be "processing" whatever that means. I thought this was incredibly fishy since there were two rebates for parallels and two for the printer, but only one was rejected. It makes me think that MacMall is attempting to bank on the consumer that is just too lazy, or unwilling to fight for a rebate. This in my opinion is shady, and I will never buy from them again, because I wouldn't want to get screwed like some of the other people in this thread.
I am very happy with the computer (brand new and sealed) and the printer and parallels (all brand new and sealed), I just can't stand companies that are not forthright with their customers. I have also purchased directly from the AppleStore and from MacConnection. By far my most positive experience was the apple store. Rebates were automatic, and I never felt like I was possibly going to get screwed. MacConnection was fine except, they dropped the price on a computer I bought 2 weeks after I had purchased it (dropped by $100) and would not refund the difference. Most reputable sellers are willing to work with a customer in this situation.
Bottom line, if the difference is around $100 (tax included) I will not even think twice about buying from a reseller, and never again from MacMall.