Would be business suicide for them to release it without an easy 1 click option (or registry tweak) to default to the standard Win 7 traditional style computing desktop, at least on the x86 platform. There is simply too much corporate business they would lose if they forced the Metro UI, and we're a long ways from people being able to productively use a PC with a gesture/touch UI for real computing or data input. Win 8 is not a heck of a lot more than Win 7 underneath the Metro UI anyways when it comes down to brass tacks - they would prefer you not know this, as most serious users won't buy Win 8 knowing that, heh. Try the Win 8 beta and you'll see it plain as day, and the differences between the current beta on x86 will not be all that different than RTM versions.
The ARM version of W 8, I do expect that to be Metro only though - it'll be the "tablet" version of Win 8.
The day comes where I am forced to use my hands like an ape fighting with coconuts on the monitor to input data into a database is the day I change to another real computing OS with a real desktop interface. We simply at not at the point where touch is a workable enough solution to force upon serious computer users, and the corporate market is a vast % of MS's business - which will be using keyboards and a mouse for a long time to come.
Win 7, for a MS product, as painful as it is to admit - is a quite pleasant experience. Win 7 is a walk in the park on a sunny day with a cute girl compared to Vista, which was nothing more than a never ending root canal comparison/pain wise. It's no classic, friendly OS like Amiga OS, but it's light years ahead of what Windows used to be. Vista was bad, comparable to Windows ME, Active Desktop, and MS "Bob" on the pain-o-meter.