There currently is work availabe.
Grab it before it's gone. We need some more points for the Formula BOINC challenge.
Generally I observed in the last weeks:
Rosetta "refills" its available work units when it drops under 400 / 500ish tasks in progress.
Rosetta is showing zero tasks again. It doesn't take long for them to run out
I grab them when I can but not for the month of Feb though. ;)