What do you like in a programming language?

As a hobby/educational project, I'm writing the specification and reference compiler for a programming language. Although education and experience are my primary motivators, I really want write a language that people would use.

So here's my question: What makes a programming language good? Specifically, I'm looking at a strongly, statically typed object-oriented language with some functional aspects, with templating tossed in.

Here's what I've got so far. They are in no particular order. Remember, this is just a wishlist, I'm not claiming to deliver all this by next month .

• Efficiency
  • Allows for (but doesn't require) optimizations.
  • Doesn't waste (note: 'waste', not 'use') CPU cycles.
  • Doesn't waste (note: 'waste' not 'use') RAM.
• Clarity
  • Clean syntax.
  • Intuitive semantics.
• Safety
  • Audited and tested implementation of standard libraries.
  • Support for exceptions.
  • Support for interfaces and their enforcement (in some incarnation or another).
• Openness
  • A liberally licensed reference compiler.
  • A CPAN-like repository of code.
• Bind-ability
  • Ability to use extenral libraries.
  • Ability to export libraries to other languages.
• Feature Completeness
  • Turing completeness (obviously).
  • Extensive standardized libraries.
• Extensibility
  • Easy to create domain-specific sublanguages.
  • Some mechanism for conditional compilation.
• Scalability
  • Full OO constructs.
  • Package/Namespace system.
  • Loadable modules where they are supported.
• Portability
  • To various OS's.
  • To various CPU's.
• Concurrency - Able
  • Good support for threads.
  • Good synchronization primitives.
  • Good communication primitives.