This is a concern for me too. I put a lot of importance on the duality between Clark and Superman (okay, I put a lot of importance on everything), and I think that's the secret ingredient a lot of adaptations and stories miss. When you use Clark and the Planet just for exposition dumps, villain targets, and as easy access for Superman to find adventure, you miss the chance for Superman to have real, human wins and (far more importantly) losses. In some ways, Clark's more important to the story than Superman is.
But I think Bendis knows this. Looking at his stuff so far, he's thrown a lot at Clark Kent, not just Superman. And he's made Clark more important, and used the Planet more, than most writers have in years. He gave us Chaz! So I am hoping that if the identity does go public (and I'm not convinced this is the case yet) Bendis manages to retain the duality of the character. What that might look like, and whether it actually works or not.....we'll see. But I am really hoping Bendis pulls this thing off, whatever it ends up being.
I dont believe in change for the sake of it, and I think the foundations of Super mythology are more than strong enough to require no tinkering. But I *do* believe in natural growth and character development. The duality of Clark-Superman has changed and evolved over time, in ways that often run far deeper than the page itself might indicate. If this is just more natural evolution and it makes sense as a viable, faithful direction for Clark? I can get behind the idea of a change like that.
And if nothing else.....if Bendis doesn't stick the landing, and even if he does....what're the odds this will stick? Even if it's good, even if this is the best idea the mythos has seen in fifty years, it is almost certainly not going to last beyond Bendis' run or the next reboot.