In mat cutts recent post he is explaining some changes that took place at google.
One of those changes is that if you type in a misspelled word in google, it will show the top 2 results of the correct spelling before showing the rest of the misspelled results.
However, misspelled domains that are targeted at type-in traffic will still be just as valuable.
See article here: What was new at Searchology?
Hope you find something interesting in there.