Unfortunately, the 'less-reflection' merge to trunk as of r12742 causes SLIME to fail to compile 'swank-abcl.lisp' as seen in the attached stack trace.
To observe this outside of Emacs, obtain a [CVS HEAD snapshot of SLIME][1], start ABCL, point *DEFAULT-PATHNAME-DEFAULTS* to the location of 'swank.asd', then issue
CL-USER> (asdf:load-system :asdf)
[1]: http://common-lisp.net/project/slime/snapshots/slime-current.tgz