Cheap Windows is probably going to help a bit with upgrades, at least if consumers can get the same discount. But if this only applies to cheapo laptops, meh.
What would help more is dropping the Visual Studio price a lot
Right now there are, I think, 4 variants of VS Express, all for different purposes. If you want a handy IDE which supports plugins and has all the different build environments (managed .NET, compiled C#/C/C++ etc.) in one, it gets *really* expensive. The US price may be around $500 from Amazon (and it's probably not the top version either), but here in Europe MS prices are well above US pricing + sales tax/VAT.
If they care so much about developers they should give away the *good* development tools.