There's probably two camps.
1. We have a good IT department
May upgrade to Win 7/8 without new PCS
2. We don't have an IT department.
Upgrade to Win 7/8 when they buy a new computer.
I am thinking at the least that all of my customers will get a notice to contact me before upgrading.
I'm most concerned about add-ons where vendors are not able to quickly upgrade their code.
This upgrade has the potential to be an ""FRX Killer"".