I wouldn't count on it. The E5-2687W is a workstation only SKU and yet it was released with a locked multiplier. If there ever was going to be an unlocked Xeon E5, one would expect that it would have been that one.
As for unlocked eight cores, I suppose there is a slim chance that Intel might release a Core i7 Extreme version later this year. I don't expect that they will because they can take those highly binned 435 mm2 dies and make them into Xeon E5-2687Ws, and thereby sell them for almost double the price.
I suppose the only caveat to that would be that Intel once released an unlocked dual processor capable Extreme CPU - the QX9775 - on the LGA771 server socket. The price point was $1499. It could be possible that Intel would do something similar now.