Just spoke with Scott from Dallas Avionics and was told there will be a 2 stage fix for my 600 EXP ADS-B Navworx unit.
Stage one will be a software upgrade that will change the SIL from a 3 to a 1. That should be available in a week or two and is a short term improvement.
Stage two will be hardware costing $299 and is a "small box the size of a cigarette pack" that will go in between the main cable and the Navworx unit. That will be available in September.
We have until January, according to FAA, to get it all sorted out.