On Bitcoin Money blog is a post describing the problems that occur at the point that funds as the result of bank transfers meet bitcoins at exchanges. Some excerpts:
"Dwolla funds are not necessarily ‘like cash’ and instead have come to resemble funds from other payment networks. Dwolla indeed will pass on to its customers any losses resulting from ACH reversals".
"Three weeks have passed now since Mt. Gox first had to stop accepting SEPA bank transfers".
"The overall impact to Bitcoin from these latest difficulties should be muted though as long as one or more exchanges with decent market liquidity continue to support each of the funding methods that directly touch the banking systems. Both Intersango and Bitcoin7 continue to accept SEPA deposits, and no less than three exchanges still support Dwolla transactions”.
"Perhaps these bank transfer weaknesses will instead show why Bitcoin could become a preferred method for transferring funds even".