There are 2 levels of uniqueness:

• session (aka work session in Eclipse) -> reported as "page view" / "unique page view"
• Eclipse instance -> reported as "New Visitor" / "Returning Visitor"

Eclipse instances are trackable by querying the stats for 'Visitor Type' and the value 'New Visitor'/'Returning Visitor'. My plugin currently counts visits and GA recognizes this and reports accordingly.
It would be nice to have a match towards the sessions, too. Unfortunately I'm still not 100% sure how this stuff works. There are cookies for this (utmb, utmc) but no spec that details the values.