Well Wikipedia is great and all, but hardly an authority on any subject. According to subsection 2.8.3 of the ACH rules it says there is a 5 day limit on reversals, and that's what my banking rep says as well (although they have been wrong before). I agree credit cards are a nightmare, they give you no support at all.
There are a lot of people who cash out stolen credit cards who would love an easy method to launder stolen funds. Credit card -> SolidCoin -> BitCoin -> MTGox would be about as untraceable as you can get.
If you take credit cards you are going to attract a lot of credit card thieves.