a) Yes. Fortunately, I have the luxury of running multiple machines so I don't have to abandon XP. For Win7, I'll do what I always do with a new OS. Win7 will get it's own machine with two separate installations on swappable hard drives - one to use on a day to day basis, and one to screw around with and break.
I've just downloaded Windows 7 and Server 2008 via MAPS (see note below). I should have both up and running by the end of next week.
b) If it works reasonably well (like XP) it will be around until Microsoft finally pries it from our cold dead hard drives. (Just like XP!
c) Ideally, it gets purchased with a new machine, but it ultimately comes down to economics: full OEM copies for new builds, and upgrades for everything else.
Note: if you are professionally involved with any of this and have your own business, you may be eligible to join the Microsoft Partner Program. Doesn't take much to get accepted. Basically you need to fill out an application; take an online course and pass a not very difficult test every so often; and have some proof you actually have a bona fide
tech business. In most cases that means furnishing a copy of a business tax permit or similar document.
Once you're registered as a partner, you become eligible to purchase something called a Microsoft Action Pack Subscription
- or MAPS for short. A MAPS subscription provides copies of a goodly number of Microsoft products for internal use in your business. Cost for a subscription is approximately $300 (US) annually.
Most of the Server products are there along with desktop OSs, Visio, MSProject, and the most recent version of Office. Some of the products (Win7 and Office) allow for up to 10 copies to be installed.
Subscribers can download these products from dedicated servers Microsoft has set up just for MAPS. You may also elect to get delivery via hard media for an additional fee if bandwidth is a problem.
All in all it's a pretty good deal and well worth looking into if you're "in the business" as the saying goes.