Clojure [1] seems to meet all of these criteria. It's a functional language where you can get away with using only a few data types, while also supporting (most of) the rest of the things you mention.
I like the idea, but I want it to be embeddable and since I'll mostly be embedding this in some syntactically C-like language, I would like the scripting syntax to not look so out of place. I updated my previous post to say as much.
Databases are fine, but blogs change infrequently and mostly serve the same static content. Caching the database-generated pages, or just serving static files, if much more efficient, especially when a crowd comes.
Can better blogs be built on top of Google's App Engine? I've been building on top of it with Go but I don't use app engine's data store, and I'm not sure that I want to. My little database is a pregenerated Go variable.
You can run a blog on a cloud platform, set up auto-scaling, and withstand a reddit / hn / slashdot crowd.
You will likely run out of the free tier and into significant spending during the spike pretty soon.
If you ran a highly interactive page that required a lot of non-trivial server-side processing, I'd understand.
But blogs serve the same static content to almost every request. I don't see why burning a whole lot of CPU and IO on it by running python/php/ruby and hitting a database many times is worth it. Serving a set of static files automatically generated by a blog engine (like Jekyll) seems much more reasonable to me.
Regarding comments: Disqus or something like that could help. Or you could turn the comments off during a spike: seeing the content without comments is a much better user experience than seeing a 500 Server Error page.
We used FPGAs from Xilinx to implement a MIPS processor for a course in school, and I remember one of the most frustrating things of the whole process was the toolkit/documentation. Compilation errors were very unhelpful, and debugging was a nightmare for most relatively complicated tasks.