The hard thing to think of is this, since the country's founding the RKBA has at least given the average joe the ability to cause significant damage to those who would attack him. These body armor suits change that. Specialized rounds or extreme skill seem to be the only good answer, and most of us have access to neither of those.
If you haven't done so, surf over to Amazon and check out Level IIIa and Level IV armor w/ceramic inserts for sale.
I've been tracking this trend for a few years now. This issue isn't going away and although more advance bullet designs exist, they certainly will not be made available to civilians. Body armor is only going to get more effective and less expensive, even now, a good level IIIa vest isn't much more than a Glock.
I'd like to see body armor become an NFA item, just like machine guns, descrtutive devices, short barreled rifles, suppressors, etc. Tax stamp, LEO sign off, fingerprints, and a very involved background check for each plate and vest.
I went through the process myself, frustrating, but doable and probably not something a would-be-criminal, even with a clean record would attempt.