you could also use the ex2200-c as a type of media convertor in this situation where the optical port on the switch connectes to the MX and the copper ports on the ex2200 easily handle the FE connections.
Making the connection to the MX a trunk port you can bring in a mgmt vlan to remote access the switch and deliver the production vlan for the FE device as a separate tag that you convert to untagged on the handoff.
Steve Puluka BSEET - Juniper Ambassador IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP) http://puluka.com/home
@damanloox: If you go for this solution, I would recommend to look at EX2300-C-12T instead as EX2200 series goes EoL in less than two months together with EX3300, EX4200 and EX4550. On top EX2200 has a 25% higher list price than EX2300 series :-)
-- Best regards,
Jonas Hauge Klingenberg Systems Engineer, SEC DATACOM A/S (Denmark)