Good old habits: notifications again
We didn't put or effort only in the mobile environment or the new declarative "way of doing plasmoids", but the general polish of the traditional desktop shell, the "most immediate need" for users is quite high on our priority list too.
A remote notification
In KDE SC 4.4, thanks to a very successful Summer of code project, is now possible to share your running widgets to the local area network. This opens a whole lot of new possibilities, but as every brand new thing, it still did not come to full potential, but is something that developers will have to play with to start to have really interesting applications.