No, because that plugin would have to manage work items and change sets (the list of versioned files), that is the planning and the source control part.
Plus you would need the EMF - GMF dependencies, part of the 200+ MB bundle, as described in "Tip: Installing the Rational Team Concert client into Eclipse 3.5.x".
Which is basically 75% of what the RTC plugin is (the rest being a link to the JBE: Jazz Build Engine).