Certainly there is our own English identity. I used to dance the Morris every St George's day, with a red rose pinned to my kit, in a big gathering of many different sides and traditions, which went on into the night. There are more than enough Morris sides to adopt that idea across the country, as well as the May morning dance out. There are a lot of re-enactors too, who could get together for an event, even local ones in a pub car park.
How about ringing our church bells? That's another English tradition, adopted in some places across the world now. No reason why we can't have a few moments of change-ringing on St George's day, even if every tower can't get a band together if it's a weekday.
Up here we have an organised St George's day celebration on the closest weekend, with all kinds of things associated with an idea of being English, including Elizabethan games, an historic flora market, mummers, and of course St George, who always wins, but sometimes only just! That's English Heritage, and they're doing other events too, including anthems at the castle from the Bettershanger band ...
http://www.english-heritage.org.uk/server/show/nav.20478dehms eh
There is so much we could do to celebrate St George's day - a concert of English music or bands on the bandstand, plays by English writers, a dance with traditional dances, eateries serving some of the traditional dishes from across the country, demonstrations and have-a-go sessions of crafts like painting roses and castles or making corn dollies associated with particular areas ... or at home - bonfires, cooking special dishes, watching maybe a Shakespeare DVD ("Cry God for Harry, England, and St George!"
), visiting a "heritage" site ... and we do have our own traditional drink. What's wrong with ale or beer? Sensibly drunk, in conjunction with a few traditional pub games, what could be better or more fun in marking the day?