Some of these changes refeer to stuff that is simply missing as an IDE feature rather than a language construct, but you get the drift..

Things VB.NET should have had out of the box:

• Multiple lines code (i.e. no "_" needed to break a line into smaller ones - much more readable code (Especially when declaring attributes - yuck!)
• Multiple lined comments
• XML help tags like C#(Why do we need VBCommenter for such a basic thing?)
• "Debug" and "Release" build folders by default. Why the hell is that missing?
• Indexed properties and arrays accessed like C#'s arrays - using "[]" and not "()"
• The same for attributes - using "<>" is *ugly*

Things C# should have had out of the box:

• Background compile
• Case-insensitivity
• VB.NET-like Intellisense for enums and namespaces writing
• Automatic creation of "()" braces on method calls -  meaning that writing the following: MyMethod myParameter Turns into: MyMethod(myParameter) automatically.(VB.NET does this very nicely - saving lots of typing time)
• With like functionality VB.NET - jeez - this is the part I miss the most....

I'd say that any languages that adopts these changes automatically becomes my "perfect" language - for the time being... :)

Update:

I *knew* I'd forget some stuff:

• Edit &  continue in both languages
• VB.NET - properties - public getters with private/friend setters making your property read only for the  public but writable for internal or friend classes

(thnks to Jan for reminding me...)