I just installed Windows 7 beta on a Hyper-V VM (1GB RAM, single proc, 127 expandable drive) and found that the calculator has changed and I like it.
Beyond Standard and Scientific there are two new modes, Programmer and Statistics.
Programmer supports Binary, Hex, Octal and Decimal and includes a slick variable length (byte to qword) binary view.
Since I’m currently working with quite a lot of bit twiddling this is a handy mode that I will be using frequently.
Statistics mode is far less interesting and has features to do things I no longer recall the usefulness of. It’s all very important, I’m sure.