Nvidia's Geforce 7600 got rather popular and more than a few manufacturers are using the Geforce 6150 integrated graphic. Sony and some others like the Geforce 7300 too. Nvidia also dominates with its MXM modules and can put even two 7900 GTX mobile cards together in SLI.
ATI missed a lot of deadlines in 2006 and these are very important in the OEM business. You have to be on time to go back to school, or Yule or you cost your customers money. ATI was all at sea for much of the time year and this affected its market share numbers big time. The biggest problem that Nvidia had was trying to cope with that much OEM business since it is more marketing company than anything else.