It is your call of course, but I know that once in the mountains a few days my opinion on what to carry changed drastically. All kinds of stuff that seemed necessary, got boxed up and sent home. I didn't pack all that heavy to start with but still sent several batches of stuff home. I can tell you that getting rid of a few pounds makes a huge difference in the comfort of the trip. iPod, GPS, and all kinds of other stuff went home early in the trip. Clothes got cut to a minimum too as did lots on little comfort items.
The one big splurge I might make weight-wise is a DSLR, but only if photography was one of the primary reasons for the trip. Memory cards are cheap and very light weight, so just take enough for all the pictures that you will take instead of carrying the laptop. If it was me, I would forget the daily journal updates and photo uploads. Do a quick journal entry only when you happen to have the opportunity without too much inconvenience. Once in a while upload a picture or two. You will be able to do this from a public library or host's home. If it is once a week, two weeks, or even three weeks fine.
Keep a paper journal and transfer it to your online journal when you get home.
As I said, I would skip the laptop entirely, but if not at least go with something like the eepc. I would also skip the Spot and the GPS. If someone at home is super paranoid and was going to pay for it I might carry the Spot, but only if it would set some very worried family member's mind at ease.
Consider using twitter from your cell phone as your means for frequent updates to home, but don't promise daily contact to any one. Cell service can be pretty spotty and pay phones are becoming extinct. I know we went quite a while at times without calling or contacting home and it really annoyed my wife because I had lead her to expect daily updates before we left.
I know that for me the one of the single biggest factors in whether a trip is enjoyable is the load carried. A few pounds make a huge difference IMO. If in doubt about an item leave it home. Once underway a while review each item and send anything that is iffy home.