Ubuntu Software store replaces Add and Remove Programmes. It does not
replace Synaptic as you figured out. It is meant to be easier for newbies to
use than Synaptic. The name store is a misnomer because it is free. But it
has brought some controversy as people think that Canonical plans on selling
software to us. They have no plans for this but the opponents always look
for the worst.

Also new is Ubuntu One which is an Ubuntu version of Dropbox that is
connected to the cloud. It is for file sharing and backup, but there are
other uses planned.

It has a new Computer Janitor, Grub 2, latest OpenOffice and GNOME, Firefox
3.5 and kernel 2.6.31 and a host of things happening behind the scene. It
boots faster and runs snappier. It has moved from HAL to DeviceKit and udev
to handle cameras and other devices. There are many improvements that are
noticeable and some that aren't.

The kernel supports DKMS or Dynamic Kernel Module Support and this is
something that I don't know much about but want to know more. It is supposed
to make it easier to update drivers after a kernel upgrade without the
necessity of the OEM releasing new drivers for each kernel.

http://www.linuxjournal.com/article/6896

I also believe that restricted-extras no longer gives you libdvdcss2 to play
encrypted DvDs. Not certain about that as I don't watch videos on my
computer. Maybe someone could confirm that?