I am hoping that Blizzard doesn't change Inferno, either, but I have my doubts after the same promise was made at the beginning of Cataclysm with the dungeons. They were hard, they were challenging, people had to CC again, healers had to mind their mana, tanks use cooldowns, and DPS NOT STAND IN THE FARKING DAMAGE ZONES, etc, etc. BUT, then the nerfs came swift and sure, and things...weren't so hard any more.
Now, I am WELL AWARE that this isn't WoW, but so what? Doesn't mean it can't happen, though I am hoping (with some skepticism) that Blizzard keeps it stance this time, but I will not hold my breath. With that said, if things need to be changed because some things are too hard due to over-zealous tuning, then that's fine and it should be done. Inferno should be challenging, but not impossible and things should overall be fair to the player once the player figures out appropriate strategies. My only other concern is that I hope Inferno doesn't promote mass amounts of skill switching, despite the Valor buff thing, but we'll see how that goes once we get there.
This has been brought up before and it is irrelevant when it comes to Diablo.
WoW is a subscription based game. They HAVE to cater to the lowest common denominator in order to keep people renewing their subs; lost subs = lost money. Additionally, in WoW, some of the dungeons at the start of Cata were too hard for a lot of the lesser players to see, and certainly this would stop them from ever seeing any raids. Nerfing that content allows people to see it at all, and the LFR system allows even the biggest failure of a player to see the raid content. And like I said, if people don't get to see this content, they'll quit, and lost subs = lost money.
Diablo 3 has no subscription fee. Normal and Inferno are the same game for the most part, anyone that does Normal has seen everything the game has to offer ASIDE from higher gear drops, certain enemy affixes etc. Whereas in WoW, if you couldn't hack it, that was it; you're not seeing it at all. There is absolutely no reason to nerf Inferno in order to cater to people that refuse to play better in order to see it, and those people can't hold Blizzards arm behind their backs because no subs are involved.
That said I'm predicting we will see some nerfs to either Inferno difficulty as a whole, or maybe just acts 3/4 or something when the first expansion is released, to remove a bottleneck so that more people can get to the new content.