I think it's good idea to add to Lazarus support for modern Windows window manager features, like Aero Glass. However, in my opinion it's not good to use that in cross-platform applications, as it's not possible to make it looking similar on other platforms than Vista/Win7. Anyway, the wrapper for this feature should be contained in Lazarus.
I doubt that linux can really save your money. as total it costs a lot more for its inconvinience and a lot of troubles and ..... so on.
I experienced a LOT of more troubles in Windows than in Linux. Also, as I have fully legal Windows 7, I prefer Linux because I think it's better OS, not just because it's free. I pay much attention to make my Lazarus applications working under both Windows and Linux.