As said, the GTS250 review was a complete sham, basically sites were only given cards if they agreed to use 4 specific benchmarks and a 5th that you could "choose yourself" out of 3 or 3 other specific games, you could only bench it with specific settings, against specific cards and quote specific prices etc, etc.
Lots of sites had a rant about Nvidia's strong arming sites into it.
As for retail, its supposedly been semi confirmed(not that semi) that to sell Nvidia cards in the USA Nvidia has been demanding detailed information on marketing, sales numbers, advertising campaigns, numbers of who sells what to which distro's and its only been doing this for a year or so, then they jump into the retail side?
BFG screwed entirely by Nvidia and pushed out and Nvidia move in to up profits marginally in the stores BFG had their strongest ties too? Also it would now seem that its Newegg and Bestbuy, the two biggest sellers in the US market in retail and internet sales, I can't imagine thats doing anything but heavily angering the remaining exclusive partners.
I've not seen, are they standard 450/460's? I imagine it would pee off partners less if it was cut down 460/450's they otherwise wouldn't be able to persuade partners to sell because there are no margins on them, if its full blown normal identical 460/450's. Well, every Nvidia card sold is stealing a sale from their AIB customers, and as they've squeezed the hell out of ALL of their AIB's for 3 years, I can't see how they can be happy.
I don't think its as desparate a move as 3DFX made, but its similar reasoning, maybe with a little more forethought, ignoring the fact Nvidia branded cards are on sale before the Nvidia staff knows about it

The simple answer is Nvidia made a 100mil loss and is facing increasing costs and lowering sales, dramatically, a quarter of a billion turn around in the last quarter, well I pointed out at the time that those kind of numbers are bad, very very very bad.
The only way I think Nvidia can prevent EVGA, Gigabyte, Asus,Zotac and the main guys from being hurt by the move is if they kill off XFX and a couple of the other smaller boys completely and ONLY sell what the other guys don't want to order. But considering the move to the biggest retail and biggest internet seller as prefered partners, I can't see them being "small time" in this situation.
As for Made by ATi cards, largely almost all cards are made in one or two places at launch and are made by ATi prefered partners and shipped out for others to put stickers on, thats been standard for years, the occasional ATI oem card is usually just excess stock without branding on from Sapphire/powercolor anyway.
The difference is, starting up selling cards out of the blue when it takes sales away from their partners = really really bad. If they always made them and always sold 10% of gpu's themselves, then Asus/EVGA/etc never had those sales to begin with, different situation.