An AppleInsider reader reached out to British Airways to ask about Passbook support and a helpful representative said they're already looking into it. In particular: "Please be assured that we will get our Passbook-compatible functionality live on ba.com as soon as we can." Another airline hopping on board the Passbook wagon is music to my ears. So far I'm really enjoying the (admittedly limited so far) functionality of Passbook.
[Source: TUAW]