To me 'Balance to the Force' means a preportion - two Sith no more no less and since the dark side is stronger a need for more jedi that is the Balance.
Anikans move to join the Emperor is, in my opinion, his original destiny being fullfilled and Bringing Balance to the Force, complete when he slaughters the remaining Jedi...
Anikan, now known as Darth Vader is required to Balance the force again when yoda dies... that being to destory the Emperor and finally leaving only one trained Jedi, his son Luke...
Once more Jedi would arise the need for 'Balance to the Force' would see the rise of a new Sith Lord...
Does this make sense - does in my mind :P
footnote - not sure what forum to post this topic in and also didin't search the forums for a similar topic cause my mouse is recharging
