Ahoy,
I added a new configurable called swank:*globally-redirect-io*. If you set this to true in your ~/.swank.lisp then we hijack the standard streams globally for the duration of the SLIME connection. That way e.g. serve-event handler output will go to the REPL instead of *inferior-lisp*.
Currently it doesn't redirect *standard-input*. That's trickier since we can get the Lisp's native REPL trying to read its input from our SLIME REPL :-).
You can also globally install SLDB as the debugger like this:
(setq *debugger-hook* #'swank:swank-debugger-hook)
But that's old news..
Cheers, Luke (who just found his first use for synonym streams)