C# 3.0 Implicitly variable types

I have previously posted about C# 3.0 new features.

The good side for
var p = new Point(1,2) is the we don't have to write that much redundant code. (like Point p = new Point(1,2))

The bad side:
The compiler won't implicitly convert to: IPoint p = new Point(2,3).
The usage of p as concrete class will lead to a lot of "concrete-class-dependency" and, eventualy, to bad design.

It is a pitty that syntax is used as a crotch to enrich the language. Look at Lisp, Smalltalk and Ruby, to see how easy is to enrich the language and to create DSLs. (ruby sample: rake, and this article)