That's kinda how I feel about the addition of corruption and chromatic resists. Once upon a time SvFire/Magic/etc/etc meant something. Then they changed how those are handled and Chromatic uses the lowest resist....but they also added corruption.....which there isn't much that handles that as a resist. So effectively making those other resists somewhat pointless because at lower levels it's not high enough to resist spells, and at higher levels those resists are used a lot less if at all. So in the end corruption resist is all that there is, and I don't know anyone who has max corruption resists personally.
Sounds like luck is going to end up being the same kinda thing. Unless they intend to incorporate luck into previous gear, then you'll only be able to get it from new gear, meaning until you're high enough to experience the new expansion you won't have luck? Does luck increase the base that we all innately have had all this time, or is it going to break a lot of stuff prior to it's addition?