I think the card has a 128 bit memory interface so the memory could make a difference.
I rekon they are doing the old bolt some memory on and hope the bigger numbers shift the stock.
Your still going to get some folks picking these up of pcworld shelves misinformed or uneducated and expect these cards to run at resolutions beyond it's abilities.
I know the 210 cards were 64 bit so anything beyond 1gb was fruitless anyway.