Is there a conditional ternary operator in VB.NET?

iif has always been available in VB, even in VB6.

Dim foo as String = iif(bar = buz, cat, dog)

It is not a true operator, as such, but a function in the Microsoft.VisualBasic namespace.

Depends upon the version. The If operator in VB.NET 2008 is a ternary operator (as well as a null coalescence operator). This was just introduced, prior to 2008 this was not available. Here's some more info: Visual Basic If announcement

Example:

Dim foo as String = If(bar = buz, cat, dog)

[EDIT]

Prior to 2008 it was IIf, which worked almost identically to the If operator described Above.

Example:

Dim foo as String = IIf(bar = buz, cat, dog)