2 plug-in tips from me:
1. Digital Heaven "DH_Reincarnation"
[
www.digital-heaven.co.uk]
$60 to buy. maybe a bit exy, but they make good things
(the tute video makes it seem pretty miraculous, but i wish i know what it was doing)
there's probably a demo you can try.
2. Too Much Too Soon "Hair Removal"
[
www.mattias.nu]
this is a more manual approach.
yes, it's called "Hair Removal", but you can narrow it down to a very small point.
works by sampling previous or next frame to fill the hole, and you can ad an offset.
i've used this for single dust spots, not continuos ones.
nick