I think it would really depend on the type of job. Workers and employers are really just contractual agreements where there is an equity stake for both sides. Employers need the workers in order to generate business, workers need the compensation. If more workers were not in as much need of compensation, they would have more leverage, but I don't think there would be any great change, it's still a contract with (supposedly) equal stakes on both sides.
Personally I think some of the little abuses might go away (unfair schedules, small reprisals, etc), but no major changes.