"Rumors"? You realize you can look at photos on the internet, right? The "new" (3 year old) Mail interface is only barely different from its previous incarnation (moving the message list from a top pane to a side pane) and IMO it's a far better use of space on a widescreen display. But if you don't like it, there is (and always has been) an option to use the top-pane style instead.
10.9 did introduce a bunch of Gmail-related bugs into Mail, though, and even now (after a quick emergency Mail update, more fixes in 10.9.1, and even more in 10.9.2) it still doesn't always update when new mail comes into my Gmail account (10.9.3 is rumored to have more fixes). How they fucked up a previously perfectly functional app like that is beyond me.
Pretty much all the other "iOS-ification" I've seen people complain about is also a non-issue, but you weren't specific so I can't help there (Launchpad? Just don't use it. Notifications? Actually quite useful. Gatekeeper? Turn it off if you're a power user. Can't even think of any other things right now).