While you have things open, you may want to put in a new panel. The kitchen by code needs at least 2-20A circuits for just the counter outlets, not counting lights/frig/DW or any other things. Plus, current code requires AFCI breakers for bedrooms. You may want to install wired (battery backup is good, too) smoke detectors. These need a 3-wire setup with the third wire as the remote trigger so if one goes off, they all do. Laser printers have gotten more efficient, but the heaters on one of them can draw some heafty current, and you may want more than one circuit to feed your computer stuff. Depends on how extensive your home theater stuff gets, one 20A circuit may or may not be enough. Got a few thousand W audio system, and a big screen, and it can get messy when the bombs start going off and the bass rocks the house! You may never get an easier opportunity to do it now. You may also want to consider running some RG6 and maybe some CAT5/6 around, too.