According to my sister, who was on a British Airways flight from London to Boston yesterday, they are just offering the normal drink service. Of course, that was yesterday, and she also got to sit on the Tarmac for 5 hours while the airport/goverment decided what to do. (her flight was supposed to leave around 9am London time, and arrive 1pm Eastern time--she didn't arrive until almost 7pm)

She was only allowed the passport, medication (non-liquid), and a wallet. They gave her a nice plastic bag for it all. Everything else was not allowed as carryon.