I am certain 3rd party developers, like Meteobridge, will revise their products to work with the new AcuRite site. It might take a little while, but it will happen. Many folks (including me) have added MB or Ambient's Weather Bridge to their AcuRite systems. I don't think there is anything to fear as far as obsolescence is concerned.
I posted a query for Boris on the Meteobridge forum asking whether he was aware of the coming change (I'm sure he is) and whether he intended to revise MB to accommodate it. Haven't heard back yet, but I will post here when I do.
Anyway, the new site is a big, big improvement and I'm sure it will be well received.