This is a rather daunting (124 slide) PDF on Sun's "Fortress" programming language, designed in large part by Guy Steele, which is designed for scientific / mathematical programming. It looks really good -- lots of good decisions (take advantage of Unicode, traits and objects, implict and explicit parallelism... well, actually, making parallelism the default for loops is a mistake...).

I do sometimes second-guess myself about whether concurrency is going to be a mainstream concern or whether taking advantage of 90% of your computer's power (once you get to more than 10 cores) is going to be a niche problem. My gut tells me that mainstream programmers cannot ignore that much of a discrepency in performance; performance is always an issue and, even though the majority of performance problems are not CPU-bound, I just feel that no one will want to say "Yeah, it's single-threaded" when the pointy-haired boss is looking for someone to blame for performance woes on a 16-core machine.

Found by way of James Governor