Doing a little CE trading today and looking at how fast the market is moving, it seems to me that (assuming the player base stays the same or grows) it's unlikely that the market is ever going to be moved around by a single actor again. Of course, it was never a problem in the first place... a single actor can only push the market within a narrow range around equilibrium, and probably buys or sells 100 blocks of CE or more in the process. That means you need to be buying or selling thousands of blocks (100s of thousands of CE) for it to be profitable. Most market manipulation was probably unprofitable or marginally profitable attempts to expand the per-transaction profit... although there may have been (and may still be) people who try to move the market -permanently- which is simply not possible. (Unless you keep pouring crowns or CE into it, but then it's not really manipulation, you're just being a market force.)
As fast as the market is moving now with this many players, market manipulation is steamrolled by market forces without any chance to cash in.
Of course, this isn't stopping -somebody- from trying to walk the market up with 10-up bids, but that sort of thing gets undone in seconds when someone wants to bid on a shiny UV and sees that the gap between buy and sell offers is very small and spams buy-crowns-now.
Maybe it's a cash player who still believes that market manipulation can create anything other than a temporary anomaly. A lot of people seem to believe that's possible despite all evidence to the contrary.
CE Prices are too high!
I wouldn't be surprised that a large group of players with high levels of strict coordination could manipulate CE prices up or down - at least for a short amount of time.