Where has STATMAN gone in SQL Server 2014?

So we've recently upgraded our environment to SQL 2014 (Enterprise on CU5) and are having some problems diagnosing performance issues, compounded by the problem that we no longer seem to be able to tell when SQL Server is updating/creating statistics.

Previously, when compiling a plan, if SQL Server needed additional statistics (we have autostats on) we could see in sp_whoisactive that STATMAN was busily working away doing his thing. Now all we get is a blank sql_text column, no query plan and a huge number of reads and only by looking at the locks do we see that there are some statistics somewhere being generated (but not which columns on what table).

Does anyone have any insight into the changes here? Is there any way to tell what stats the optimizer has asked for? I know we can once the plan is compiled (thank you Paul White) but we have a fairly large data warehouse, so sometimes the stats collection operation takes a significant amount of time!