I'm not entirely sure, but I think that the 'aero' looking theme will be optional on W10M. You may be able to switch it back to a regular wallpaper and transparent/solid tiles. I don't think that's gone away I just think it leaks more often this way because it appeals to a wide range of people. Personally I like the look of the WP8.1 Start but we'll have to wait and see what happens.
Edit: oh and by the way, it will definitely be running on THIS! :)
I'm not entirely sure, but I think that the 'aero' looking theme will be optional on W10M. You may be able to switch it back to a regular wallpaper and transparent/solid tiles. I don't think that's gone away I just think it leaks more often this way because it appeals to a wide range of people. Personally I like the look of the WP8.1 Start but we'll have to wait and see what happens.
Edit: oh and by the way, it will definitely be running on THIS! :)