5 guys is overrated for burgers (Too fast-food style), but their fries are amazing.
But considering there were camera crews waiting for him to order a burger, you're crazy if you think this wasn't a 'look how regular I am' photo-op. If Obama actually just wanted a burger, he'd have sent an aide to get it,( or have his personal chef make him one) and it would have been a lot less trouble for everyone. Considering the secret service has to vet every location the president goes, this was probably 2 weeks in the planning.
If I had to pick between Obama and Bush which president is more likely to give the secret service an aneurysm by randomly declaring that they're stopping at a burger joint, all my money would be on Bush. I doubt either ever did, or will though.