lordjedi said:
First, those timelines aren't changed each year. MS releases an OS and each OS gets the exact same type of support. Vista's support will probably end sometime in 2012, but I haven't looked at the timeline for it, so don't quote me on that.

Second, Windows 2000, XP, and Vista are not very similar in their source codes. Windows 2000 is close to XP, but neither are close to Vista. Vista isn't even close to Windows 2003. The biggest change in Vista was with the driver model. The video drivers were completely rewritten. Those changes could not be backported without completely rewriting the driver model in XP. That would end up making XP just like Vista, which would be pointless from Microsoft's perspective (it was nearing it's end of life as it was).

I wasn't really speaking in terms of planned OS time lines or what Microsoft defines as support. I'm talking about the kind of reasonable functionality support we'd get if Microsoft had a competitor or two that were able to earn some of their business. As it is, there aren't really any practical ways for me to run my software or programs on a different operating system made by another company and, as such, Microsoft has less incentive to make me happy. My programs work in 2000, XP, and Vista yet Microsoft limits me to go with the last one or else pay a price.

It's interesting how you mention Vista's re-written driver model since that's a perfect example of what I'm saying here. I'm sure the brand new driver model for Vista is really cool (and stuff) and I don't begrudge Microsoft wanting to make money for their work there. However, newer hardware effects don't ultimately rely upon a "driver model" to work. There's no reason XP's driver system couldn't have given gamers access to the latest, 3D-hardware driven, graphical effects. Even if it didn't work as well as what Vista offers, it wouldn't be hard for Microsoft to expand functionality in this tiny way.