As it stands, you can use windows XP on a 300mhz with 192 megs of memory, and it's just about as fast as 98se and windows 2k were for me.
Yet here we are, a 2.4ghz with 512 megs of ram and a 128mb graphics card that only supports DX8.0 is not enough for vista?
You could use a PCI video card with no acceleration on XP and have no issues. Hell, microsoft recommended 256 megs of ram for multitasking in XP.
Microsoft is just further proving they are nazis who care for nothing but cash, they will not get their way with me. nLite will be out there for vista someday... and I will be waiting.