I'm a big fan of Lua and Go's use of multiple return values, nil, and simplified error handling, (No exception 'types'). I think the problem with 'typing' Exceptions is that it means you are using it to record and pass describable\known state similar to return, instead of being reserved for unknown state. For indicating predictable failure states without using exceptions, I think multiple return values as used in Go and Lua is a much better paradigm. To recap Steve's post, opening a non-existent file in Lua:

    =io.open 'sdfasdf'
    nil	sdfasdf: No such file or directory	2

The first value returned is nil, the 2nd value is a string containing an error message, and the 3rd is an integer error code. This allows you to write most code using 2 state boolean logic:

    f=io.open 'sasdasdfsf'
    if f then -- nil is a boolean 0

whereas in Python, one often has to reason about 3 states due to the use of try\except blocks. Even though you are not using typed Exceptions, multiple return values does not discard any state about the error if it is desired:

    f, err = io.open 'sasdasd'
    print(err)

In Lua (not Go), when you combine multiple return values with an assert() function of the form assert(boolean, error_message), you effectively get a mechanism for making exceptions optional:

    > =assert(io.open 'sdfasdf')
    stdin:1: sdfasdf: No such file or directory
    stack traceback:
    	[C]: in function 'assert'
    	stdin:1: in main chunk
    	[C]: ?

Although Go does not appear to include assertions at all, arguing against them in its FAQ: http://golang.org/doc/go_faq.html#assertions