The blog references Spolsky who has marked it expired. Perhaps he has changed his mind.

Problems with error codes:

Too easy to ignore.

Errors and normal return codes get mixed.

Often difficult to pick a distinguished error value, 0, -1?

Problems with exceptions:

Too easy to ignore. How often do you find empty exceptions?

Too many types of exceptions, The Java libraries are particularly guilty of this.

Adding a checked exception can break code all over the universe.

This blog post fails the "well-reasoned argument" test:

Pros of Return Codes:

1) Return codes are typed

2) Return codes are cleaner than exceptions and can have additional associated data

3) Exceptions are easy to ignore

4) Return codes integrate well with third-party code (how would you use Exceptions and not blow your client's call stack?)

Error handling is hard, let's go shopping.