Up to a point, about the speaker, who cares? (8)
I believe the answer is:
somewhat
'up to a point' is the definition.
(I've seen this before)
'about the speaker who cares?' is the wordplay.
'about' indicates putting letters inside.
'the speaker' becomes 'me'.
'who cares?' becomes 'so what?' (I've seen this in another clue).
'me' inserted within 'sowhat' is 'SOMEWHAT'.
(Other definitions for somewhat that I've seen before include "To a moderate extent" , "To a small or moderate degree" , "Partially, to a degree" , "To an extent, a little" , "To a certain extent" .)