They've come to realize it now because there are huge companies that are coming in and some governments that are in favor of it but the counterpart is to regulate transactions that happens inside their country.
Is this really an indication that the Big banks will be more accepting towards Bitcoin?
Not that really but more banks would come to have their own service but first, they're likely to buy chunks of bitcoin and might treat it as their bitcoin reserve supporting whatever service that they might come to it that's related to bitcoin.