I didn't think so either.
With the signing of Landry, it became clear that there would be a logjam at the 4. Since Landry wasn't brought in (at his current contract, no less) to be used as trade bait, it was clear that someone else was probably going to go. Who? Not sure. Discussion for another time. However, now WITH the Landry injury, that "logjam" isn't so apparent anymore, so players aren't as expendable as they probably would have been. Not to say that they aren't available for the right price, but that we don't have the same flexibility given the situation.
landry's injury will likely hurt the kings' competitive chances in the short term, but i'm not sure it effects their roster flexibility or bargaining position as a trade partner this season. to repeat what's already been said, the kings likely didn't acquire carl landry with designs to move him anytime soon. i did not agree with the signing of carl landry at the current length of his contract, and i remain an opponent of the signing, in general, but he probably wasn't going anywhere via trade, at least not this season...
that said, if landry is out a full four months, well then that conveniently schedules his return for right around the trade deadline. meanwhile, either jason thompson or patrick patterson will have been "showcased" for potential trades, particularly without landry available to eat into their minutes/production. most mid-season deals don't occur until just before the deadline, anyway, so should the kings decide to move either thompson or patterson at the trade deadline (or even hayes, perhaps in a larger package with thornton, etc.), they'd likely already have landry back in the lineup, or his services would be returning to the team shortly...
again, i think this injury does more to hurt the kings' competitive chances, as well as provide a chemistry/cohesion setback, than it hurts their trade position. landry will have considerable rust to shake off by the time he's fit to hit the basketball court again, but i'm not holding out hope for a playoff push in the second half of the season, so it wouldn't bother me if the kings moved one of thompson/patterson/hayes at the deadline, in spite of landry's limitations upon returning from injury...