No official date yet, but this thread should keep us posted. The MERCS team have added a Sefadu tab to the online store, though at this point it doesn't lead anywhere...
MERCS shirts are in development, and a poll has been put on the forums as to what design they should run with - Keizai Waza VS Sefadu. Check out the forum thread here and cast your vote!
Bags, Dice, Tokens and Maps
Check out the thread for the full run down, but here is what Brian Shotton had to say on the upcoming MERCS merchandise:
MERCS Bag from Battlefoam
We just approved the prototype about three hours ago. We'll talk to BF about showing the sample. We think this will be available in Sept/Oct. We should have a sample at GENCON for show.
Faction Dice from Crystal Caste (or was an agreement reached with someone else)
Tokens from GF9
Done. Look for a press release very soon. We should have some for sale at GENCON.
Maps from GF9
European Production with West Wind will start by the middle of August. This will allow retailers in Europe to get our stuff cheaper.