Nope, still there. They aren't taking synaptic out of the main release until software center has matured a bit, 10.10 or maybe 11.04.
You can always install synaptic from software center as it looks like it will stay in the repos, just not in the default install of future versions.
I see. i had heard that the Software center was supposed to become default in 10.04.
the Software Center is ridiculously easy to use.
you know anything about Ubuntu One?