To start, I'm aware of the debate over the value of programming certifications. It's not really the subject of this question. Suffice to say that I believe studying for a certification will greatly help me in understanding .NET.
I've been looking at the .NET certification options, starting with exam 70-536, which is for .NET 3.5. .NET 4.0 is on the way though, with a new CLR version among other changes.
My question is: should I start working on a 3.5 certification considering that 4.0 versions may be on their way?