Yeah, I'd go with that, a good cross platform framework is very handy, and Qt certainly fits the bill.
I've written a small desktop twitter client as a hobby project and it compiles without modification on Windows, Linux and OS X (and NetBSD) due to being written entirely in Qt, and I've not found anything whilst writing it I wasn't able to do entirely within the framework.
I did also once look briefly at the mobile side of things and was able to bring up a very simple reading only twitter client on a Symbian emulator in about 20 minutes with Qt due to being able to reuse a good chunk of the desktop back end code. From a developer point of view this is great.
@not quite like linux
Good point, NetBSD is a very good example of how to do low level cross platform stuff well. However to be fair to MS, whilst it's not a true micro kernel, NT isn't that far off, they did initially try and put as much stuff in the user space as possible however the first version was quite slow due to having much of the gfx layer in user space as I remember. They are also working towards putting much more of this right too, the sound layer in Win 7 runs as much in user space as possible I think. It's probably more historic reasons that have resulted in the proliferation of kernel mode drivers, which is something driver signing is aiming to address arguably.
Also, the cited benefit of NetBSD, the HAL, is present in NT too, it did start life as a cross platform OS.
I've always thought that the underlying NT stuff was perhaps quite a good little OS struggling to get out from under the cruft of Windows piled upon it.