But you know, that (almost) nobody is buying this stuff at full boxed retail price. The OEM license for Dell will be around $50-70 for customers, the hardware is bought in big unit counts too, and gets appropriate discount, so the PC's will go somewhere between $600 - 1200 depending on some other factors like graphics, RAM and HDD models/capacities and branding.
Not many people MS Office boxed version. Most private people will pirate it (and Microsoft is actually more happy about it then if they would use alternatives like OOo). Many will also go legal and use OOo or get a copy from the company they are working for.
Businesses will go volume license, and the package of software / seat will also circle around $200 - $400.
That said, I'll still continue to use Ubuntu + OOo + other open source software. I also build my PC's myself, so I get the best fitting solution and opt out of the MS tax (and be it just because of the principle, though the financial aspect is also counting). Considering the current economic downturn (and the fallout that is following as we speak), more businesses are and will also go a more open source way, though not the majority and many only partially (i.e. Windows 7 + OOo).
One thing is true though, the Win 7 (re-branded Vista) will increase sales of PC's for a little time, especially since Christmas is approaching.