No, users can't do most of the tasks in Metro (Modern). The default tiles, or whatever the term is, link to the Modern apps that aren't the same as what you find on the Classic desktop (such as Internet Explorer - two very different versions). That 95 year-old will feel like Alice (in Wonderland) when he "takes a bite" from the Metro Internet Explorer, and then takes a bite from the Classic desktop Internet Explorer.
You can't stop thinking of Win8 in terms of previous versions of Windows. You shouldn't have to. There is a concept called look and feel. A well-designed system should have and customers expect a certain look and feel. What Microsoft seems to be telling us on each new version of a product they put out is "We didn't know crap about how to display and organize the interface before, but we got it right now." Then, out comes the next version of Windows or Office, menu items, ribbons, tiles, icons, or whatever get moved, changed, or deleted, renamed or some other obfuscation to leave a user befuddled on where to look for a possibly non-existant feature.
I think Microsoft did a brilliant job of establishing an excellent look and feel with Windows 95. The control panel was the most logical of any other version of Windows. Now, one of the entries in the control panel is something like "Printers and Other Devices". That's real informative. If you have something physically attached to a computer, that would be a printer or other device. Right-click on a printer and two of the choices to select are "properties" and "printer properties".
Back to Palmetto_CharlieSpencer's comment that you rarely have to see the Classic Desktop. That is true if you can figure out how to get the classic applications over to the Metro (Modern) start menu. It can be done, but I think most casual users would have to struggle to try to find the process and many of those would still not succeed.
Fortunately, there is a great deal of business-essential software that will not work in Windows 8, so I will have some breathing-room before I have to try to assist users with Windows 8. Hopefully by the time software developers program for and certify Windows 8 for their products, users will have already purchased a Windows 8 computer at home and had their relatives/friends walk them through the muck called an interface on this new OS, which appears to be an otherwise very fast and solid operating system.
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