I seem to remember one of the issues with S80 was attracting developers. The target audience for them was tiny compared to s60. Similarly funding a separate UI for a much smaller volume, I assume, was not viable.

S60 has evolved a lot since S80, and the applications that are available for it are growing daily.

The reviews of the 9300 were not positive (no wlan, no camera, slow, bad audio) but it sold well.

The E90 is getting mainly positive reviews.

Touch screen is an interesting one, until recently (apple) they were pretty much slated as being less easy to use for a phone. Now, the tide has turned.

But phone R&D programs do not happen in a week!!!