With multiple DCs, we won't have the luxury of read repairs. The nature of WAN networking also means that there is a higher probability of network issues leading to inconsistencies not covered by hinted hand-off. This makes running cross-DC anti-entropy repairs at regular intervals more important in a multi-DC setting.
The issue with repairs is their cost. We need to establish whether
1) there is a chance that traditional full repairs could be cheap enough to schedule them once per reasonable interval (every <n> days, with n <= 7?), or
2) if we can make incremental repairs work with reasonable repair performance and impact on read latency.