"OK.. I know this may have been asked already but here it goes. Umm, what is the reason for vista?"
I bet M$ loves questions like above too, because it's a subtle compliment as to how well done and successfull the Windows XP campaign overall was.
Windows XP & Vista Side-by-Side
Functionality aside though, you have to remember that M$ fundamentally was & despite its enormous size still is a "for-profit" organization with regular stockholders that expect no less than a worthy return on their investment.
If you also review M$'s history, you'd notice the OS, most especially the versions based on the Windows NT 5.x Kernel brings in boookoos of money, some of which ironically has afforded M$ the wasteful luxury of dabbling into just about anything & everything without considering the odds of success to such moves first.
With that out of the way, your beloved XP would have been around for roughly six years by the time Vista goes GOLD and after that long hiatus, you'd figure it's about time their R&D team ushers in a new or at least a much revised software (OS) that will further harness the preponderant hardware and technology that's emerging at this period of time and in the near future.
Finally to the part that I understand but disagree with - the cost.
While the asking price for Vista may not be dirt cheap, I do not think Vista is priced out of the reach of everyone, M$ created the branching to specifically accomodate this and I believe it is actually fairly average.
Full versions
- Windows Vista Home Basic: $199
- Windows Vista Home Premium: $239
- Windows Vista Business: $299
- Windows Vista Ultimate: $399
Upgrade versions
- Windows Vista Home Basic Upgrade: $99
- Windows Vista Home Premium Upgrade: $159
- Windows Vista Business Upgrade: $199
- Windows Vista Ultimate Upgrade: $259
The problem is with most people going for something that's out of their base requirement.
The Home Basic Upgrade is as low as $99.00. IMHO, anyone that "critically needs" the $399.00 Full Vista Ultimate to accomplish their day-to-day computing task must be able to afford it - if they cannot afford it, they need to re-evaluate their computing priorities or business model.