Things a good programming language should do, even if they are Hard, and which your own favorite language surely fails to do some of:

• help clone things.
• help do equality/comparison testing.
• have 'where' as well as 'let'.
• have something like newtype deriving.
• help automatically clean up resources other than memory.
• have as many things be 'first class' as possible.
• support reflection/introspection/mirroring.
• support named parameters, optional parameters, and partial application.
• do varags in a way that doesn't suck.
• not use case sensitivity for anything too important.
• lean toward being as close to statement-free as possible.