...In terms of gear what I wrote 4 years ago in minute details remains mostly true today:
Bernard, this is an excellent writeup and is spot-on re. equipment.
One little tip I will add is that I rotate an undershirt during the day. Bernard mentions merino wool and I am basically head to toe in it (Smartwool) and I keep a spare shirt and socks available. It is almost impossible to keep my back from sweating while carrying a pack and traveling uphill. At the end of the day and sometimes during the day I will exchange my base layer shirt with a dry one and hang the wet one on the back of my pack to quickly dry. This is not just a comfort issue, as getting sweaty on cold windy days can be scary and dangerous. A huge advantage to merino wool over poly is that merino wool is practically odor proof, whereas poly will begin to reek.
Re. condensation - I use a double-wall Stephenson's Warmlite tent in winter and, even with venting, it is difficult to manage condensation. For all other seasons I have found the Big Agnes Ultra Fly Creek UL1 to be very adequate for one person. The only condensation I ever see in this tent is on the floor when it's pitched on snow.
Re. packs - I use 30L and 45L Cilogear packs which are expandable to 40L and 70L and easy to cinch down to keep gear secure. They are a lightweight climber's pack so have no outside pockets, but the lid on the top serves to stash easy to reach items. They have a customizable strap system which is very handy. I almost always use the 30L unless I'm gone for more than three days. Tripod gets strapped on the outside, along with crampons/ice axe if traveling on snow. These packs are great if you need a low-profile pack - for climbing or pushing through brush, but I think a standard pack rides a bit better.
Keep camera handy in a small lightweight front pack. Like Skip says in his article, the front packs designed for cameras are too bulky and heavy. Do you really need extra padding to protect your camera from your stomach? I put my E-M1 with one wide-angle zoom, storm cover, Lee Seven5 filter kit, extra batteries, some microfiber in a plastic bag, and remote shutter in the main compartment of a Mountainsmith Kinetic TLS. In the smaller front pouch I put map, compass, GPS, notepad, TP, and a couple food bars.
I use a storm parka that is designed for climbers, so the pockets are high to clear a climbing harness. That also makes them high enough to clear your pack harness and front pack, thus making the pockets useable for stashing energy bars, gloves, hat, etc.
Lightweight is key. Many backpackers strive for ten pounds, but they aren't carrying camera gear and comfort items like an air mattress.
I've got my system down to under 30 pounds for overnight, more in winter. That includes everything including 2L of water.