Technically in order to be A+ certified on the 600 level exams you have to take the 601 Essentials and one of three others. If you just take one exam you aren't certified until you take the 602, 603 or 604 along with the 601.
With the new certification it is just two exams, an essentials and one other exam (no more choices). Still two exams. Not sure what you are talking about modification Verg, this two exam setup has been in place since 2006 when they brought out this exam. The new 'modification' on the 700 level exams is you only take to set exams.