If this bill passes, it will introduce a tremendous incentive for those who are current on their payments to ether stop paying or fall behind. Why keep paying on a mortgage when you can stop paying and possibly get the bank to reduce your principal by at least 10%? And, if the appraisals are honest, then there is a potential that your principal amount could get reduced by up to 50% or more.
No way I would keep current on an underwater mortgage if this bill were to pass.