Probably more bragging rights than anything as it is now... but it won't be long before games start to use >64mb often enough that having 128 megs of memory would make a big difference.
Besides, do you know what this means? 2048x1536x32bpp gaming!
If anything, they're probably the ones losing more money. Releasing a new product consists of all the press releases, the marketing costs, etc, all that crap just so they can get the product known.
That is, unless there really are enough people stupid, crazy, or power hungry enough to buy the product every 6 months.