So if you're using Desktop Presenter I'd assume you're using Ustream Producer.
To do the same with New Livestream you could use Wirecast Studio (which Ustream Producer is based on) but you'd need to feed Wirecast Studio into a Livestream or, alternatively, use Wirecast's Virtual Camera Out to feed Livestream's Producer software (Procaster but for New Livestream).
Of course the other alternative is use Livestream's Producer and use its built in screengrabber to grab ProPresenter.
All the above keeps in on the Mac.
If you must use the Windows computer for streaming then you have to get the Mac's output to the Windows computer. If you're using Wirecast and the Mac is on the same LAN as the Windows computer, Desktop Presenter can send video and audio over LAN.
Otherwise you're going to need to hardware the two computers. How you do that depends on what MacBookPro you have.
I'm not sure what you mean be MiniDV to HDMI. There is MiniDisplay and there's also Thunderbolt which looks the same as MiniDisplay.