Yes, MB5-705 is the successor of MB5-858. Since I have been re-routed by our local Prometric test center.
No, the test content is very different from the old one. My preparations based for MB5-858 have been pretty much "useless" when I tried to pass the new exam. Maksim's statement is right and there is hardly any learning content posted on the Microsoft Learning page!
Rgds,
Martin