Um I know how you could overcome the "people thinking its close to final problem"
Seriously - here's how -
First during the install have a dialog come up saying "This is a beta version, it's no where near final, feedback on new features and other improvements you'd like to see are welcome"
Second - When the user launches the game the first time they get the same message with a 5 second wait (so they have to read it)
Third - The galaxy loading screen would be the first message
Fourth - Default unit names would all be "This is a Beta" "It's not Finished" and "Feedback Welcome"
Fifth - upon exiting the users background would automatically change to "We hope you enjoyed your experience with the beta"
Sixth - The windows XP boot screen would be replaced with the Galaxy Loading screen
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Then again if all else fails you could just create a "You forgot it's a beta" site over on YTMND.com similar to the current You Forgot Poland fad...
Or not - it's your call. Personally I'm pseudo glad it got pushed back to end of march - because the start of march for me is uber busy and I don't want to have to divide my time between a game i want to play and work. It just occurred to me that this thread should be re-titled "End of March pushed back until beta release"