Its seriously close approach undoubtedly did alter its orbit, but since we didn't see it until after it had passed it's likely very difficult to work back through its old orbit.

The Minor Planet Center did have this to say:

2002 MN

Object is flagged as a Virtual Impactor by SENTRY (JPL) and by CLOMON (NEODyS)

Ephemeris is based on 6-day-arc elements from MPO 32042. Last observed on 2002 June 23.

Further observations? VI: Continued observation necessary

I remain convinced that we need to have an orbital asteroid watch program, stationed out beyond all the $hit floating around in cis-GEO orbit. Manned (or man-tended) is preferable, of course, to fix anything that breaks and to upgrade equipment as necessary. But I'd settle for a robotic one as a near-term solution.

Here's hoping that we don't have to get smacked to get the politician's attention,
Kadet Ken