We learned that Geforce 9800 GX2 is the heaviest card around and that it might be trouble to ship a whole system based on it.
The card, with its huge sandwich cooler, is simply so heavy that it might break the motherboard during transport. This might be trouble for big OEMs who will sell complete systems, as no matter how gently you secure it, it still might break the board.
Just try to imagine if you plug two of these cards in a SLI motherboard: it simply doubles the chances. Still, we wouldn't make a big deal out of it as it will be hot, big and heavy, but at the same time the fastest thing around.
In the super high-end market, this is what counts. If you are the fastest, you win, and you can forget about everything else.