According to The Guardian, new research has been done that analyzes the more than 10 million words used between 1800 and 2008.
The scientists say that words are constantly in competition with each other and the use of spell check and strict editing has cut down on the number of misspelled and nonsensical words that lead to the creation of genuinely new words. It is the loss of these types of words that have led to the greatest change in vocabulary over the last 10-20 years.
Words created by errors are not the only words that are dying out. Synonyms are fighting for dominance as well. The story gives the example of Roentgenogram and radiogram, both of which have been soundly beaten by x-ray.
During their research, the scientists found that wars significantly increased the number of new words to be assimilated into a language. According to the researchers,”‘This can be understood as manifesting from the unification of public consciousness that creates fertile breeding ground for new topics and ideas.'”
The scientists concluded that historical events have a great impact on the birth of new words, but things like spell check are putting limitations on that creation.
Read the full story, Study reveals words’ Darwinian struggle for survival by Alison Flood.
English Major for Life 
Note that the article in The Guardian does not, in fact, say that misspellings are going away; rather, it indicates that new words are not being created at as fast a rate as in the past, which can be attributed in part to spell-checking programs.