There really is no "from" -- there is just 'where the coins were sent last time they were sent somewhere.'
If that 'somewhere' was a shared wallet (like a mybitcoin account) where all the incoming transactions get mixed up, knowing what address they were sent to previously is worse than useless information. You might decide it is a good idea to try to refund bitcoins to that address and end up sending them to some random mybitcoin user, and NOT your customer.
Adding possibly-worse-than-useless features to the bitcoin GUI is a bad idea. Am I missing some other reason for wanting to see the last addresses to which the coins you received were sent?