I only have to repeat: Win7 will not be gone. At least while the compatible hardware is produced. After that it will be runnable in a VM. Even XP is available today. Or ... perhaps you are worried that the KMS at Microsoft will no longer be issuing keys? Then run your own, for yourself or for others. Plenty of businesses use private KMS today, as it is required for Win7 Pro (it renews the license every 180 days.)
Ok, not ‘gone’. But quickly overtaken in the consumer marketplace at least. And I bet a lot of businesses too. It’ll be faster than 7 replaced vista.