afaik Aero was deliberately disabled by Microsoft and 'officially' dropped. You can however apparently get it with Stardock's WindowBlinds 8.
Stardock Corporation - Products
If by Aero you mean transparency, I can confirm this works just fine in Windows 8 using WindowBlinds.
Just fired up my Win8 vm, no problems with the Winkey it works as expected.
As yet I'm unable to update to Win8.1 to carry out tests as Microsoft have screwed up the release of language packs and 'real' English is not available. Without some registry kludging Win8 then refuses to allow the Store update token to be downloaded. As far as I'm concerned that defeats the object of a 'preview'. I can only install an iso that zaps all previously installed programs.