That's precisely the point of ARCs, and nowadays publishers love to use non-traditional medias, like Blogs, fan sites etc. Tons more ARC are distributed around, and leftovers are often given away in contests weeks before the book is released etc.

And if Tor is sending out copies before Oct. 27 after all, there's no harm no foul in publishing reviews - that would be why they send copies to people in the first place. But for TGS, it appears every reviewer who asked have been told "Sorry, no ARC printed for TGS, we can get you a copy for release day".

When reputable people/bloggers with established ties to publishers (incl. a few experienced reviewers like Larry from OF and Ken of nethspace, Pat's Fantasy Blog, Adam from Wertzone etc.) start posting reviews, the odds jo-blo poster on a MB has also gotten a copy somehow will be increased a little, but for now you can count on those reviews being fake or from copies obtained illegally.

Normally, there would be more than Jason having a review up by this point. Back in the day, TL, Wot Encyclopedia, Wotmania, Tarvalon.net would all have non spoiler reviews up by this point, and some online media would publish theirs too. There may well be more reviews down the line for all I know, but it's also well known how much Harriet, Brandon and co. dislike spoilers - an this ought to be respected. Some love to use spoilers and half-spoilers as a mean to generate hype, but it's never been the case with WOT. Back in August Brandon didn't even want to mention in Q&A vague stuff he was aware had been officially released - even which two story lines were the focus of the book. He knew it was around, even told people who wanted to know where to look for the info, but he wouldn't speak of it openly (nor does he do on his blog, where he's extremely careful about the information he shares - no doubt knowing very well it's gonna be everywhere after that, and considered legitimate to spread without warning).

The secrets of the book being spread around would not harm Tor's sales, but they sure would piss off Harriet, Brandon etc. Most fans want to discover those for themselves in the book itself - not by accident coming on a MB, whether the spoilers are real or invented by morons with nothing better to do than pulling starved fans' legs.

We waited five years, what's five more weeks before we can judge TGS for ourselves and with a fresh eye anyway?