Тоже видела этот пример:) Специально спросила знакомых бритишей и погуглила форумы, где на этот вопрос отвечают носители. Все говорят, что разницы почти никакой. Из-за этого:
There are four verbs that are virtually the same when used in the present
perfect or the present perfect
continuous: live, work, play and
study. So you can say, "I have
studied English for five years" or
"I have been studying English for
five years." All other verbs have
very different meanings when
used in the two perfect forms.
Вот еще небольшое различие:
How long have you lived here?
You might ask this question of
someone who is a permanent
resident. She or he might answer: I
have lived here for 50 years. And I
plan to die here.
2. How long have you been living
here? You might ask this question of
someone who is only there on a
temporary basis. For example, you
know that someone studying in Los
Angeles plans to return to her
country after graduating from a local
university. So she might answer: I
have been living here for six months,
and I really enjoy it. But I miss my
country and am eager to return as
soon as possible.