Regardless of whether or not Sony users want video and better high ISO, the fact that Sony is not incorporating them will make them lose market share.
For example I never use MLU and DOF preview on the a700. The other who has the a300/350 and so on were bitching about their bodies not having MLU and DOF Preview.
And it's not like video is taking away anything from still photography anyway. The price difference is hardly worth the debate when you compare the D90 and a550.