I'll write it another way...
Those upgrading within the free period take your time.
To those not upgrading within the free period...
When Cakewalk drops support of Win7 or Win8 for Sonar, because the latest Microsoft libraries force them to do so, much like when they had to drop Vista support, don't say I didn't warn you! Also please don't expect the wait for that to happen to be as long as Vista had.
Not only that your drivers and plugins suppliers will also be forgetting about these OS's.
Yup people are still running unsupported Vista (getting increasingly difficult I suspect) but we can't guarantee this scenario in future.
It's gonna be a few years at least, but this may happen sooner that you think (not like it was in the past).
Cheers..