Another thing that I should mention in the context of this post - and the comment trail after it. On this blog, I do an awful lot of "thinking in public" - I tend to post my first impressions, not after long cogitation on an idea. Which means, my initial take on an idea does not always represent the sum total of my thinking on a subject - and a mostly dismissive reaction doesn't mean that I'm not discussing the idea with our engineers.
Having said that, bear in mind that our engineering team is engaged in a pretty darn big project - we are building a system that is as large and comprehensive as J2EE or .NET, with a fraction of the engineers that Sun and Microsoft have. Sure, Smalltalk is marvelously productive, which is why we are able to stay in the game - but we do have resource limits, and - as such - a large part of what I do is prioritization.