James Kilpatrick's language column this week is on choosing the most precise word for your meaning. He covers the differences between "now," "currently" and "presently."
For example, take the New York Yankees. (Somebody, please take the New York Yankees!) Are they presently, currently or simply now leading the American League East? The trouble with "presently" is that it means not only "at present" but also "pretty soon." When the receptionist says the doctor is presently with a patient but will be with you presently, we have a muddle.Of course, most of the time you need none of the above. "They are leading the American League" says what you mean as much as "They are now leading the American League."
The trouble with "currently" is that it suggests the first-place Yankees may not be there long. (This is a suggestion based more in hope than conviction.) The word we probably want is simply "now."
I'd disagree with Kilpatrick's assertion that "currently" suggests a temporary nature that "now" does not. They both suffer from this affliction. There are cases that "now" is necessary, but I almost always use it instead of "currently." Who even says this word? It sounds stilted.