I've read that those 110mn NV42 chips can clock up and offer serious competition to the 6800GT, they are just crippled with DDR only memory. Stick some 2.0ns GDDR3 on there and you'd have a fairly hot little card.
I suspect if the pricing of these GPUs was cheap enough someone would be tinkering :)
Could end up like with the 4200 - people copying that of the 4600 and being cheaper
Do keep in mind that the NV42 110nm chip only has 12 pixel pipes and 5vp there is nothing to unlock.