That at the 2 year mark they would release a Major Upgrade which they call a Service Pack and at the 4 year mark there would be a New OS Release which was a Development of the Existing OS. So Vista had a Service Pack Released when it was about 2 years old and 7 was released when Vista was approaching 4 years of age.
This Service Pack/OS roll over was to continue for the next 10 years before it was to be replaced with the next iteration of the Microsoft Development system. To me at least it seems that Microsoft has more or less kept their word and has been releasing Service Packs around 2 years after they release a OS and a new OS around 4 years after they release a new OS.
Of course what they do next is anyones guess as as yet they have not told us what they are planning on doing but as the existing system has worked well I can see no reason for them not to continue with it.
At the Vista Release Microsoft very clearly said that they would never repeat the mess that they made with XP selling 2 OS in parallel at the same time like they did with 98SE and XP as most people clung to 98 and didn't want a bar of XP so they where holding OS Development back and they also very clearly said that they would never again have a OS life as long as XP was as it hurt them way too much.
They where right on both counts when XP was first released most people wanted 98 as there where issues with XP that where not really solved till SP1 became available and it was considered more like ME by a lot of people and XP was around for too long as there where many people who where using computers that had never used any OS but XP in their entire lives.
Keep Up with TechRepublic