In the short term it means they will redeploy their mobile missiles and probably retarget some warheads at the NMD sites, in case of war with the
West.
In the long term, more sophisticated decoys and maneuvering RV's, probably using long reentry (maybe skip) profiles using the ionization plasmas to
cloak them from radar. AFAIK it's all stuff they have been working on since we hopped on the NMD bandwagon anyway, but no doubt now they'll go the
extra mile.
It
does not mean they're going to nuke Poland and the Czech Republic next Tuesday