This isn't really a new concept.  There is already a visa available to foreigners who invest $1 Million or more in an American business, or $500,000 or more in specific targeted employment areas.  I think it is the B-5 visa, and my understanding is that is the easiest to get (if you have the money).

My guess is that to spur activity in the real estate market, they are willing to expand it beyond businesses to include the purchase of real estate.  And, I'm sure they already screen visa applicants on the terrorist watch list (for what that is worth).