There is a new system coming out, the Powerflarm (www.powerflarm.de, you can switch the language on the top right). It does the same like the Monroy without the external antenna (so it doesn't have direction for Mode C transponders), but it has ADS-B. It seems to be the first ADS-B receiver to show traffic in a portable system. It shows Mode C/S targets with distance and altitude, ADS-B and FLARM targets have the direction, too. Flarm is a system used mainly by gliders in Europe, it uses a GPS for the position and broadcasts it. Other units receive the data and show the position. It will interface with all major GPS brands like Garmin 496/696 and runs on batteries, too. Seems to be a complete solution (all different systems in one box), the only drawback is that it lacks direction for Mode C.
I played with one at the Aero fair in Friedrichshafen, it is very compact and the screen is great. I'll give a Pirep when it is available.