Speakers A and B simultaneosly in different rooms

Make sure your amp is capable of driving both pairs of speakers simultaneously. Your impedance is halved. In other words, if the impedance for each speaker is 4 ohms, the ohms load is 2 ohms. The ohms load is normally a nominal figure & is seldomly a minimum figure. Some speaker switch boxes have circuitry that prevents speakers from seeing dangerously low ohms loads, but I don't think all do.

Speaker boxes are ok, as stated, if your amp can drive both sets of speakers. Although running at least, and probably more than 20' of speaker wire, after splitting the signal through a junction box, with all of those extra termninal connections and the cheap wire inside the box....well, not for me.

You can get the same sonics as if you had a separate front end in the other room by running two long interconnects, balanced would be great, but 20' RCA's should be fine to a second amp(s) in the second room and then normal length speaker cables. If you don't have dual outputs on your pre, then even Y adapters on the output of the pre work fine, with liitle or slight sonic degredation. Although dual outputs on the pre is the way to go.

One consideration in using the same preamp and amp to drive speakers in different locations is getting the volume right in both places at once. After being frustrated by that situation I found the best solution for me was to run two outputs from the preamp and add a second amplifier with adjustable gain to power the second set of speakers.

Most amps don't have adjustable gain, of course, but some from Parasound do and I had good luck with an older Yamaha power amp with gain controls on the front panel. Once you've got the relative output of the two amps set about right you shouldn't have to adjust the gain very often. Another advantage of that setup is that if you want music in only one of the locations you just turn off the appropriate power amp.

Thank you for all this valuable imput!
I like the idea of running two different amps through dual outputs from the pre. Currently I have been running two rca cables (one a 20 ft. extension) out of my source ipod(lossless encoding.)One through the headphone jack (not as desirable) and one out of the dock. Does anybody have an opinion on whether this set up (or dual rca from any source with dual outputs) is better or worse than a preamp with dual outputs.
Thanks!

Dylano, I'm not sure I understand your question.

Are you asking if the output from an iPod going is going to be as good as the output of an external preamp fed by that same iPod? What is the rest of your current setup, how are you amplifying the two iPod outputs?