Just did a fresh install of 12.04, and for the first time didn't have synaptic. So, I tried seeing if I could find the packages I needed (mostly TeX and dev stuff) in the software center, but no such luck. Back to synaptic it was, then.
So, why did they remove synaptic, if you can't even get at most of the packages through the USC? in the answers to this question, it was claimed that synaptic was "redundant", but this is obviously not the case.
Before saying that USC completely replaces synaptic, just try installing a dev library using USC..
aptitude
is the way to go :-)