We're not ultralight but my wife and I have it down to 40-44 lbs. for both of us, including all racks, panniers, bags, tools, pump, etc., everything except the bike and bottles. We're very comfortable. One think I haven't seen mentioned in this thread is electronics. We were surprised at how much our total weight in gadgets was. How do you evangelists deal with these things? I'm talking long tour here, being out for weeks.

Cell phone. Really need one to keep in touch, emergencies, reservations, things go wrong, etc. OK, then you also need its charger and cord.

Kindle. If you're going foreign, or even if you're not, it's nice to have travel documents of various sorts, maps, hotel web pages, lists, reservations, a book or two, etc. Easiest and lightest is to bring along a Kindle. Then you're also going to need it's charger and cord.

Camera. Then you're going to need a spare battery and a battery charger.

Garmin. If you're touring with a Garmin and camping, you'll need its charger and some sort of battery pack(s) to recharge it when you're in the field.

Lamps and blinkies. It's like these don't even exist. We run fore and aft blinkies whenever we're on the bike. In Europe, there's aren't little stores everywhere. If one is not to be a slave to shopping, one will have to carry at least one set of spare batteries for each blinky. Headlamp for the head: gotta have one of those. Headlamp for the bike: gotta have one of those. More batteries. We tried to reduce total battery weight by using devices and packs that used rechargeable AA batteries as much as possible, then carried an AA battery charger, along with 8 AA rechargeables. However our rear blinkie uses AAA and our front uses N.

All these devices, their batteries, and chargers weigh something. So what do folks do to minimize these weights? It's true that many devices can now be charged off a very light USB charger, but many devices still want their own chargers.