I spent the summer in Egypt with a fairly large group and never heard of anyone having trouble with getting money out of an ATM.

Citibank doesn't charge me any fees, and none of the ATMs I used charged a fee, so I wasn't limited to Citi ATMs, either. Your hotel will undoutedly have an ATM, so you should be fine.

If you're worried, bring some extra US dollars with you as a backup. You can either change them (plenty of places to do this), or, if you have small denominations, can probably get a lot of people to take them instead of pounds, even with the weak dollar.