If BFL ever gets their production going smoothly then you will never see ROI (IMO, based on what I have read) - and the fact that ASICMINER will start producing units as well....but hey dont do it for the profit.
Litecoins *could* still provide an ROI, it just depends on how many people switch over to it (and switch over successfully... I tried 4 litecoin miners and they all crashed for me!)