Whoa long thread. I hate jumping into long threads, too damn much to read. And quote for that matter; you quote a post, 3 pages later and all your points have been made, and there's 5 pages more to go.
Yet small threads die quiet deaths. Ah, Internet how I hate thee.
To be honest, while I'm not all that keen on the flavor of D&D WotC's been pushing for the last few years, I don't really care too much about the individual races. Besides, there's probably some copyright/IP issues here anyway; WotC can use new(er) made up races as brand identity, where they wouldn't be able to do that with elves and dwarves as easily. WotC sure as hell can't copyright elves, dwarves, and goblins or put them under IP since they're just too common in fantasy/folklore etc.
As a DM though, I am in my right to ban things. For one, I might not want a list of playable races/classes as long as my arm or longer for reasons of balance. There's no way I can know how ALL of this stuff is going to work together, and trying to run a campaign that includes everything and the kitchen sink can get unwieldy. If I want that, I'll run Synnibar.
Also, with something like the PHB2, I don't necessarily want to just plop something into my world that might not have existed before. That makes it harder for me and the other players to suspend disbelief. If a player wants to get cranky because he wants to run something out of a splat or even core book he just bought, let him volunteer to DM for a while. Another reason is that I might not have seen the book in question, and I want to have a rules reference so I know things are being run more or less legally -- some players aren't above trying to pull a fast one on the DM.
Basically, when a campaign starts, the DM needs to be upfront about what races and classes are allowed, and stay consistant. The players should READ whatever handouts the DMs give them beforehand to this effect (though the DM should really make an effort to keep the page count down, because players won't read more than 2 plages of this stuff. K.I.S.S. applies here). After the campaign starts, a player shouldn't assume a DM is going to allow any new race/class combo that appears in a new book.
I liked the approach 3e OA took in the book's intro; that the book was presented for the DM to pick and choose which elements he liked for a setting. One problem I have with the whole PHB/DMG/MM
x setup is that some players just assume because it's in the book, it has to be allowed. That's always been a problem really, but in previous editions, new stuff was labeled as "Optional. Check with your DM first." 3.x had Rule 0 which was bascially to this effect. I don't know how 4e is handling this. And as someone already said, 4e's been mixing classic and newer stuff up in multiple book releases which might complicate the issue.