Qt 4.6 doesn't work well with VC++ 2010. So I decided to install 4.7 (currently still in beta).
If you want to do that too, I suggest to have a look on what Chad Liu says on nabble.com. I found his post very useful.
Actually, the Chad's post is about installing CGAL, but that requires Qt 4.7, so I just skipped all but the relevant part - that is, point 5.
All worked fine and smoothly, with only a minor glitch: at 5.3 Chad forgot to nominate the name of the file to edit, Structure.cpp, but was easy to find it out.
In any case, till the binary for VC++ 2010 won't be available, be aware that you need to have some time available for the job.
After that, I've also downloaded Qt Creator and I started using it. Cool. I suggest you to try it too.