JSON-LD challenges related to Activity Streams (was Re: JSON-LD vs. JSON: pro vs. con?)

Rather than having an open ended discussion on the pros and cons of 
JSON-LD vs JSON in general, I suggest we focus on the specific issues 
related to using JSON-LD in Activity Streams.

Indeed, the call earlier this week clearly showed a strong interest from 
the WG in using JSON-LD. However, I understand this is not without some 
technical challenges. So, it would help if we could list those so we can 
discuss them.

Thanks.
--
Arnaud  Le Hors - Senior Technical Staff Member, Open Web Standards - IBM 
Software Group