Lookups are such a critical piece of Salesforce and the Lightning Component Roadmap is still not prioritizing this for the upcoming Spring Release. Building your own version of a Lookup has some extremely odd behavior - any reason why things such as a Tree Grid or Carousel are prioritized higher than a Lookup which is the foundation of Salesforce?
https://help.salesforce.com/articleView?id=lightning_components_roadmap.htm&type=0
Hi @Chris Pearson , it is not that we are not prioritizing it. It is because Lookups have a LOT of special logic based on different standard objects. As a result, it is a multi-release effort. In Spring '18 we are planning to deliver lookup field support as part of lightning:inputField for lookups that you can choose a single record for a single object. We plan to also grow the support for lookups over time to support multiple records and multiple objects but it is not a simple effort.
FYI -
@Alexander Lovell