I can't see SWTOR becoming as big in my life as EVE is, for two simple reasons:
1, I don't have the cash for a permanent MMO subscription. I don't make huge light of it, but I'm mostly playing EVE on ISK-bought PLEXs, and only occasionally tapping my RL money for subscription fees.
2, RL time allotment. I'm hugely in love with EVE's strategic/competative nature, as well as the tactical knowledge required to win PvP engagements. I just can't fall that much in love with an MMO that doesn't feature such, although SWTOR's addition of dynamically changing "classes" is a step in the right direction.