No, Plex Home Theater is only a client (this is not a function of rasplex but of all Plex Clients)... If you are looking for local play capabilities XBMC is what plex is based on and is built this way. There are multiple builds with XBMC, the standard Debian wheezy build does not support XBMC.
Also, you can have a XBMC with a Plex plugin if you would like both PLEX and local play support.
Sure, you can sync content from server and watch it offline, but you still need the connection to the server in the first place.
How does that not meet the OP's use case? Yes, at some point, the file needs to come from the Plex server - that's where the metadata is sourced. But once synced to the storage, it is available anytime, whether the server exists or not.
Plus syncing in this manner adds overhead when you could just use Openelec XBMC and Plexbmc.
Having a singular interface is very desirable, and this would provide that. PlexSync does quite a bit more than using XBMC with manually copied local media does. It offers the ability to transcode prior to sync. It maintains watched status with the plex server. It seamlessly brings back in the full library access when network connectivity IS there, and just what is synced when it is not. It simply works better for mobile usage. I do hope that Plex will add PlexSync to the base PHT list of features, and then it can be built into Rasplex. until then, my Pi sits unused and I use my phone's HDMI output in my RV running the proper Plex app.
Funny but, few situations beyond an RV that causes your requirements... basically RV and boat:
Hotel - internet allows you to stream and there is power and a TV...
Car - Most kids would probably just use a ipad or Mom's iphone...
Plane - Cell/IPad...
Interesting use case but, limited audience...
Hotel internet is rarely of a good enough quality/bandwidth for proper streaming.
Many cars/SUVs have built in displays these days, sadly usually fed by a crappy DVD player - easily upgraded with a Pi and Plex (if this worked).