The combo of mouse/keyboard i'm using right now.... i don't plan on changing for a LONG time. The keyboard i'll probably have for ages.... the mouse.... probably until it starts to show signs of age like my MX1000 did.
Microsoft Natural Ergonomic Keyboard 4000
Logitech MX Revolution
As for hiding wires..... i've also seen wires that are pretty much entirely flat. they basically get stuck to the wall with some kind of adhesive, can go just above existing trim pieces along the floor, you could probably even paint the exposed side if you really wanted to try to hide them. I just kinda ran the wires for my two rear speakers along the same wall and butted it against the trim. i usually have too much crap piled along the wall to really notice the wires. lol
As for wireless speakers/headsets compared with mice...... mice tend to use RF wireless (or.... at least use RF for BETTER wireless. bluetooth... yeck). not sure exactly what type of wireless signal headsets, or the rear speakers on some of the 5.1 surround setups use... but i don't really remember it being RF. They do tend to have a lot more possibilities for picking up interference, or not being detected by their own wireless reciever/transmitter/whatever. Not to mention that yes, by getting wireless speakers, you're eliminating speaker wires, but you're gaining an extra pair of power wires. So unless you have a power outlet near where you'd place the speakers..... or would prefer having a somewhat thick extension cord running along the wall to power the speakers rather than quite small speaker wire.... they just don't make sense. lol