This is something I am considering/about to do too. I have recently moved to QLD from Tassie, and am planning on spending up to 9 months overseas walking next year. Tassie seems to have consistently different gear requirements compared to pretty much anywhere else in the world, given the density of the scrub, propensity for difficult off track walking etc. That's not to say that you can't go walking with lighter weight stuff, and plenty do, but the level of experience, care and skill is going to have to be
significantly higher. For some people, that's worth it.
However, looking at the conditions in places like South America, the US, India, Nepal etc where I'll be walking next year, a lightweight or ultralight approach appears much more likely to be safe and doable. This is not to say that the walking there is not hard, or that the conditions are not tough, but just that terrain, and especially local botany appear to be more lightweight friendly.
I currently walk with a One Planet pack, which weighs ~3kg. I have a few tents, the lightest of which is my Tarptent Scarp 2 at ~1.8kg. I typically tend to wear a Mont Tempest raincoat, which in XXL comes in at pretty close to 1kg. A typical weight for a week-long walk would be around 25kg I would think, including food. This setup has definitely worked for me in Tassie, and I expect that when walking in Tassie I'll continue to use a similar setup because it is what I consider practical and safe. Everybody's opinion on this will vary, and I'm sure there are some ULers out there who would scoff at me. I bet most of them don't walk off-track in Tassie.
Regarding your comments Wayno, I don't think that there are many tents which will cope with 100MPH winds... I've been in some serious wind on the Western Arthurs in my Nallo, and whilst it did stay up, I didn't sleep much, what with the tent being pushed just about flat every time a big gust came through. Having said that, I agree with what you're getting at, and think people need to be sensible with their gear choices, and adaptable to different conditions. One method will not work for all places. It seems that if you wanted an UL shelter for serious weather, pyramids have the best rep, but I just can't get over the idea of having a pole in the middle of my sleeping area.
Having said that, I'm looking forward to going lighter next year, and hopefully being able to cover more ground/feel less sore at the end of the day. I'm in the process of doing research on various bits and pieces of gear, but seem to have settled on quite a bit of Zpacks gear. It seems to fit in the right niche for me - extremely light, but still very functional and well made. I'm planning on buying a Zpacks Triplex, an Arc Haul backpack and probably a Challenger raincoat. The Arc Haul is rated to comfortably carry loads of around 18kg, which is a few kg more than its slightly lighter compatriot, the Arc Blast. It's also made of supposedly slightly more durable Dyneema/ripstop hybrid material. The Triplex seems to get great reviews from all who have used it, and what sparse data I can find suggests it does passably well in bad weather. It clearly won't be as secure as my Hilleberg Staika, but that's the trade-off for lightweight. And besides, I think there are probably houses which are less secure than the Staika!
Along with this, I'm looking at some new down gear from PHD in the UK, though predominantly for my partner, who gets very cold! 1000FP down and the best shell materials make for what seem to be seriously warm, seriously lightweight bits of gear. At a very serious price too!
None of this will be cheap, but that is the trade-off for getting the best gear I guess, and especially so when being a weight weenie. I imagine that I will still be able to use this a bit on some Tassie walks too, particularly places which are better tracked/more frequented (OLT, WOJ, Frenchmans etc), meaning I'll reduce my cost per usage, making me feel better. I'm sure that learning to take more care with my gear, as well as tent placement and other considerations, will also increase my confidence with using my gear in general, which is an added plus. Overall, I expect it to be an interesting experience, and am just hoping it doesn't go pear-shaped in the middle of some South American range!