David, I know the difference. I can swich too. I can swich to RPG  or Cobol too. My productivity is bad in all :)

However my statement is can a normal programmer switch and be as productive as before in a few weeks.
My experience in large projects is  - NO they can't
Sure they understand in days the difference but your brain has during the learning of your "first" language found ways to do things faster.
Depending how long time you have programmed the time to for your brain to chang pattern is one important factor.

Personally I think VB is better to read and write but if someone asked me what language to start a project in I will recomend C#.

And if a developement department with all VB coder shifted to do all programming in C#  I had added 15% cost for the first year.

Voted for C# because the little programming I know is in c#. No one in my team knew VB before they started working on DNN. Majority of my friends outside the DNN world are Java or PHP and most can tackle c# but not VB. Also my understanding is that anything new coming out of Microsoft, is done first in C# and then when everyone complains they dig out the VB version. 

Let me tell you something else. I heard the other day on the BBC Radio 4 >> that every 14 days a language dies. By 2100, more than half of the more than 7,000 languages spoken on Earth—many of them not yet recorded—may disappear. IMHO this pattern will be repeated in the IT world I suspect.  It is Natural Selection that we would find some languages will soon or later die this is especially likely to happen in recession, when organizations have to save money and drop projects that are not needed. So let's not be too sentimental about it, it is going to happen at some point in the future. 

Salar

---