(Longish reply, sorry
Another possibility may simply be competition with each other. I started hearing about all this when Yantis bought EQBeastlord and EQDruid - suddenly every class site was reporting offers from either Yantis or IGE or both. It may simply be that Yantis' acquiring of those two sites touched off a race to get their advertising up. IGE is hardly going to sit by while Yantis gets his adds over all the class boards.
Having said that, I wouldn't be too surprised if Sony DOES eventually start selling pp/items/etcc. I'll admit I don't personally like RL money being spent on this stuff, and it's not something I would do personally, I think it's pretty clear that fighting against it is a losing battle as long as the companies that run MMORPGs don't want to use the courts to try and shut people like Yantis and IGE down (for very good reason - there's no garauntee they'll win, and I'm pretty sure Sony et al are not keen to hurry the day when this issue finally goes up before a US court).
The problem I see with Sony selling pp/items etc is the following:
The items they sell really must come from the existing pool of equipment in the game. If they start actually creating items to sell, they will do far more damage to the game than Yantis, IGE and company have done combined. As much as I dislike them, those companies *usually* only sell stuff that enters the game world via legitmate means. Obviously, there is the occasional dupe or exploit, but most of the time it's "legitimate" items. However, if Sony only sells items that already exist in game, that means someone has to sell items to them first. Now if Sony starts offering money for plat and items, would any player *seriously* not take them up on that offer? I'll be honest, it would tempt me for sure, and there are many, many people less worried about selling items for RL money than I am

. In that environment, I can see the "expensive" end of EQ in-game trading vanishing overnight. People would be *forced* to buy high-end stuff from Sony. I hope the developers would recognise the damage that would do to the game.
I just don't see a way for Sony to be selling (and buying) items for RL money without seriously screwing up the game.
One thing I can see SOE doing without many problems (and something that doesn't bother me nearly as much as buying plat and items) is auctioning accounts. Something like that is actually in SOE's best interests (a chance to retain revenue from a retiring player). They could either simply take a commission or simply buy accounts outright and resell them (less likely I think, as they probably wouldn't want to spend money on a character they'd never sell). They could use a bidding system to sell them, and then the owner gets to take legitmate control of the account, with never any fear the original account owner can yank the account back. I'd imagine Yantis' account auctions and playerauctions would vanish almost overnight, simply because people could buy a character in complete security and comfort from SOE.
Cheers,
Sorran.