I can't see it myself. Allardyce would leave himself desperately short of cover in the centre of defence unless he has a replacement lined up. And, at the end of the day, Tomkins is not what Newcastle need.
Talkbollocks are trying to convince us that the rumour they started last week is true but I would say it is strong odds against personally.
Am I concerned as a West Ham fan? To be honest no, providing we source a reasonable replacement. Tomkins has not, in horse racing parlance, trained on. He will always be limited by lack of pace and I fancy he will never be more than a Premiership squad player, sadly.