Right now no, since Maru uses SlimPort for streaming the desktop to your display. SlimPort eats up the USB pins that you would need for connecting up a wired keyboard/mouse via USB-OTG [0]. Wired keyboard/mouse will become possible when we support other methods for display streaming in the future like wireless.

[0] https://groups.google.com/d/msg/maru-os/rsSpHZ0DIJA/mEfp_J9M...