According to WZOR, Windows 9 will be similar to the desktop OS we know today. He claims that Microsoft is planning to bring the old Aero interface back, but not as we all know it. That's all he teases regarding the Aero interface, but he also claims that Windows 9 will make an appearance in a years time, Much sooner than expected.
Regarding Windows 10, it appears the operating system will be something rather different. WZOR claims that Windows 10 will be a full 'cloud OS', and that an internal desktop concept will be available on September 1st. As this is an 'internal' concept, we doubt it will be seen by the public.
With Windows Phone and Windows RT, he claims that Microsoft is planning to merge both operating systems together. He doesn't give any more information regarding the matter, but it has been rumored several times in the past that this is Microsoft ultimate goal for both Windows Phone and Windows RT.
WZOR also claims that more details regarding everything you've read here will be available in September.
Of course, this information is coming from a 3rd-party source, so we ask you to read with a grain of salt. We assume 'Windows 9' and 'Windows 10' product names are codenames and not currently the actual names of the operating systems.