Well, that all depends. As I have mentioned before on this blog, the communist regime launched similar schemes in the mid-1970's. These programs caused a spike in birthrates for three or four years before the rates dropped to even lower levels. The communists learned the hard way that material incentives are simply not enough. Orbán's initiatives, though admirable and noble, will mean and do very little in the short-to-mid term if it is not supported by the right kind of motivation, that is by a spiritual awakening or, in some cases, spiritual deepening among the newly married couples.
If the newlyweds approach their marriages and (hopefully) children from a spiritual perspective, then the efforts the Hungarian government is currently expending stand a chance. If, however, the vast majority of these newly married couples are motivated to marry and have children for purely materialistic (economic) reasons, then Orbán's programs will end up exactly where the communist programs ended up - in failure.
For those interested, link to the article describing these developments is here.