Just saw this, made me happy:
http://github.com/rspec/rspec-core/commit/c1d600cd4367fb24a333c3f27f3b27693745ad14
So you can now run autotest without a bunch of (uglier) hacks just by adding the file autotest/discover.rb to the root of your project with this inside:
Autotest.add_discovery { "rspec2" }
note that you’ll need at least rspec version 2.0.0.beta4 (beta3 does *not* have this)
and once again return to autotest bliss…
cheez!