Last month Nokia announced the 5800 XpressMusic device that is the first S60 touch screen device rolling out from Nokia. I haven't had a chance to play with the device yet so I cannot personally comment on the touch screen or optimization Nokia made to S60 in regards to touch, but Kevin Tofel and Steve O'Hear both have spent a bit of time with the device and offer up some initial thoughts.
Both Kevin and Steve mentioned the lack of a capacitive touch screen being an issue on the Nokia 5800 and in this day of capacitive touch screens (the iPhone and T-Mobile G1) it seems people now expect finger touches to register on the screen. The days of non-capacitive, stylus-enabled screens may be on the way out as people's expectations and needs change.
It also seems that there are some inconsistencies in the operating system as sometimes you need to single tap and other times require a double tap, with zooming in and out sometimes needed as well. I was also quite surprised to read Steve state that the web browsing was sub-par with the S60 browser.
I think Nokia probably had to launch something with a touch screen to stay relevant in the mobile space, but for a mobile phone I am not sure you really need a touch screen and find that non-touch screen devices generally are more responsive, stable, and have better outside viewability.
Other Nokia 5800 reviews and previews appear at: