The benefit is you can verify the hashes and compare them to the MSDN iso that will leak to torrent sites.
Today is the day though. I haven't seen it yet on my VL site or any of the technet or MSDN subscriptions we have. That and I am sure there will be other things like the RSAT and Visual Studio 2012 released too. Today is one of those big PR days for MS and I am sure they will make a big deal about it.
Well in Redmond (Microsoft HQ) it's 7:51 am so give them some time and it should be out in the world before dinner.
i think sizes between leaked and mdsn will differ because the offical microsoft iso will probably contain updates that the leaked one didn't have. just a guess though. remember that wzor leaked the rtm 1-2 days after it was sent out to oem partners. microsoft would have had time to update the build with bugfixes before finaly realeasing it officaly on aug 15.
On MDSN it says Windows 8 Enterprise X64 is 3329 MB. And I checked my wzor iso file. It's 3329.19336 megabytes big. That's pretty damn equal in size. The leaked windows 8 pro wzor 64 bit image is 3415.92188 mb. MDSN tells you it's 3416 MB big. but look 3415, 92 rounds of to 3416 mb. So I don't think it's fake. probably microsoft who put some updates in their offical image file.
check the sha1 i can upload them i have very fast connection in upload and download and msdn subscription but unfortunately msdn now is crap! i cna put many languages too !