You'll see the claim that "5e is not old-school enough." on the web, in the forums and G+ land. I've been a critic of the whole thing (elsewhwere not here). Not thrilled with a starter set sans-character generation (it took a page and a half in a basic set). In all honesty however it better not be too old school.
If 5e is too old school what would the point of it's purchase be? If 5e did a really excellent job of producing a house-ruled retro-clone do we need it? It's going to need a fair bit of new to get this guy to buy in.
Let's go back 15 or so years. There were tid-bits on the new D&D and I was intrigued. At the time I was playing a 4th edition Gama World Campaign that was nearing a natural death and looking into starting up a D&D campaign but wasn't sure if i was goign to go with the Cyclopedia or AD&D (in some form) so the idea of a new edition of D&D intrigued me. I followed the news in Dragon Magazine and online where I could find it (mostly EN-world). I picked up the 3.0 PHB at my local shop when it hit the shelves.
I eagerly started flipping through the book reading snippets and boy oh boy there was a host of new stuff. I started a cover to cover read and maybe got a chapter in when I literally threw the book down on the couch next to me thinking to myself "they changed too much!". After that bit of nerd-rage I thought to myself "Well it better be different, you just paid for a new game.". It was different but after a good reading I found a game I liked at the time. I played it for several years because it was different.
I wasn't a fan of the 3.5 revisions (most of the "problems" it solved just were not problems in my eyes.) and while there is heart and energy in pathfidner it just didn't go the right direction for me. A friend lent me a copy of the 4th edition D&D books, he wasn't happy with them but respected my opinion and wanted my opinion after I read them: I was no fan. Difference can be good and bad.
The new edition of D&D had better be different enough to encourage purchase for me, if it doesn't stray far enough from previous versions there really is no point in a purchase it's a crowded market with plenty of near-D&D and non-D&D alternatives and I have enough older stuff to last until the end of my life. Despite the vast amount of stuff I have i'm willing to pick up a new version if it offers something new, an alternative, and is something worth playing with others. I have no need to spend my cash on the same-old same-old. Why do people want to keep buying the same thing again and again?
Let me say it "5e D&D had best be just different enough."