I'm definitely glad I posted this. Thanks everyone for the huge list of suggestions. I've got tons of food for thought now, as well as a few more questions.
It seems like my biggest areas of opportunity aside from my bag are the pad, windbreaker/shell, and filter. I could potentially save 1.5 lbs or more for around $50, which is excellent.
PAD - After doing a bit of quick research, it looks like along with my 13 oz, I'd be dropping about 4 points in R value, which seems pretty significant. I know everyone sleeps differently, but what are the lowest temperatures you've taken a Ridgerest to comfortably? Also, my feet tend to get cold when I use shorter pads. Do you guys just prop them up on your pack or something?
WINDBREAKER/RAIN - The DriDucks have definitely got me interested. Like I said, I do some bushwhacking here and there. Has anyone had problems with the DriDucks ripping under similar conditions? If it's a rare problem, they're inexpensive and I've always got duct tape and super glue, so it shouldn't be an issue. If it's a regular problem, I'll probably want to save up for something more durable.
FILTER/TABLETS -The Frontier Pro looked tempting until I saw that it only filters down to 3 microns. It'd probably keep me safe, but I'm still not sure I'd trust it. The main tablet sources people use seem to be Aquamira, MicroPur, and the previously mentioned Aquatabs. The argument about Chlorine Dioxide makes sense and the prices of MicroPur and Aquatabs seem to be reasonable enough to make me consider switching. One question, though: Sometimes I hike in areas where the only water sources are muddy or tannin-rich. I can get pretty good water out of those using my filter, but does anyone actually use tablets in situations like this? Or do you bring along a filter at those times?
Then again, there was one time where the only thing I felt comfortable doing was boiling...
As far as repackaging liquids goes...I assume you all bring 100% deet and use it sparingly in order to save on weight, right? How much of it seems to do the trick for an overnight? For a week? How much sunscreen do you bring?
As far as eliminating entire gear pieces by seeing what I don't use and browsing this forum, that's actually what I've been doing for the last month. On my last trip, I used everything but the emergency blanket and squeeze light. I will probably ditch the emergency blanket once I get a better quilt, but the squeeze light seems worth its .5 oz just in case my headlamp batteries die or I lose the thing. I probably can pare down my first aid kit and repair kit a bit more than I already have. I've found that I carry far more duct tape than I'll use on a trip, and I already mentioned that ace bandage. Definitely worth another look.
Again, thanks to everyone for their help! I carried 22 lbs w/ food & water for my last trip and it was amazing. The idea of getting that down to 17 or even 15 is awesome.
Edit: Dan, my friend's got my scale right now so I can't weigh it, but as I recall the camera itself was 5.7 or 5.9 oz with the battery and SD card. Maybe I have a heavier version? The case is fairly lightweight (~2 oz?) and pretty much bombproof. I need that, because I dropped my last camera off a firetower... (It still takes great pictures, but the screen is broken).