It seems like everyone is turning onto Haskell these days.
At Rails Edge last week, I saw a few telltale signs that some of the speakers (including a few members of the Rails core team) were playing with Haskell. In one case, a speaker was flipping through TextMate projects, and briefly displayed one project named "Haskell". In another case, the presenter's browser had
a link to All About Monads centered in the middle of the bookmarks bar.
Of course, I had to take the opportunity to see why these speakers were interested in Haskell. One speaker was looking into Parsec for some insights into language design (for DSLs, probably), while another was revisiting the language after he tried to learn it a few years ago.
It turns out that a few members of the Rails team have informally chosen Haskell as their language of the year this year. Nothing formal, just a bunch of folks who hang out on irc periodically trading bits and pieces of Haskell.
Somehow, I think this bodes well for both Rails and Haskell. The more people who actively look into Haskell, the easier it gets for others to follow. And the more people who take ideas from Haskell in order to apply them to other projects, the stronger those projects get.
(It's interesting that the Pragmatic Programmers put forth the idea of language-of-the-year in 2002, dubbed Haskell the language of the year, and haven't updated it in 5 years. ;-)