HTF recently reviewed a wireless HDMI solution. Gave it pretty good marks. You can read the review here
When it comes to wireless speaker systems, the consensus is that they aren't really worth it. First, they aren't really "wireless" in the true sense of the word. The speakers must still be wired to the "wireless receiver" that, in turn, must be plugged into a wall outlet for power. Since "surround" speakers should technically be placed to the sides of the listening position, it's just as much a challenge to wire the two speakers to the wireless receiver unit as it is to wire them to the AVR in the first place. For surround back speakers (used in a 7.1 setup) this isn't as big a concern, but reliability of the connection and the time it takes to "re-establish" a connection in the event of a dropout can be a significant distraction.
Hiding speaker wire is really quite simple. If you have carpet and baseboards, there's almost always a "channel" underneath the baseboards where you can tuck in the speaker wire. Fishing wire through walls really isn't that difficult with the right tools, and there are a ton of other products out there that can be used to conceal speaker wire.