Actually, MS plans that,
devices running Windows 7 and Windows 8/8.1 would receive a free upgrade for one year after the OS shipped. Devices upgraded in this fashion wouldn’t just get a one-time update code — Microsoft committed to keeping any upgraded device current “for the supported lifetime of the device.” Exactly what those words meant has never been clear. But new statements out of Redmond may have shed some light on that topic...
The big question consumers have been asking is whether Windows 10’s “free upgrade” is going to contain some sort of gotcha clause that ropes people into paying a lump sum later, or being marooned on an unsupported OS....
Microsoft has fought for years to pull users off of old versions of Windows, and the “supported for the lifetime of the device” language is likely designed to allow the company to move to a different support model. That doesn’t mean Microsoft intends to charge outright for future versions of the operating system, however. More likely, Microsoft wants users to treat Windows upgrades the same way that Android, iOS, and browser updates are typically treated, with the majority of users jumping for new versions as soon as they’re available. Businesses or individuals that choose not to do this may have the option of purchasing extended phone or technical support, in much the same way that companies can now. http://www.extremetech.com/gaming/204900-microsoft-sheds-light-on-windows-10-revenue-future-os-pricing-plans
For my Windows 7 systems...... For sure I will not be upgrading them to Windows 10 for a few months after 10 gets released. I will be waiting for the dust to settle.
I will probably wait 6 months to see what has happened to others before installing 10 over 7