I have almost everything I need to hike. The only thing I absolutely need are new boots. My faithful, wonderful Merrils finally died this spring. I am, however, looking into upgrading a lot of my gear for the hike and replacing a few items that are worn out or lost. When I first started backpacking I got inexpensive (read: heavy and bulky) gear and I'd like to replace a lot of it with lighter, smaller, more efficent equipment.
The items slated for replacement:
Pack - going to a smaller and lighter model
Sleeping bag - I think I'm going to switch to a down bag. I have no complaints about my synthetic bag. It's given me 10 years of trusty service, but down is lighter and packs smaller.
Rain Gear - In the past I've used cheap $0.98 ponchos and a heavy storm proof foul weather jacket. The poncho was light, but the jacket kept me dry. I'd like to find something that combines both qualities.
Long Underwear - What I have now is fine for the warmer months, but I'd like something better for the cold nights down South in early spring.
Music Player - I don't need it, but I want it. My current mp3 player doesn't have a lot of memory and needs to be plugged into a computer to recharge the battery.
Stove and Cookset - Again, my current set up is great, but I can reduce my pack weight if I replace it with a lighter stove.
Items to buy:
Maps - I only have maps for the Northern half of the trail and will have to buy maps for the South.
Boots - I had a great pair of Merrils that only gave me one blister ever, but after 500 miles they just didn't have any life left in them.
Camera Case - I dropped it in the ocean and it was last seen sailing merrily towards Portugal.
Socks, Underwear, maybe a couple Bandannas - These items are a little worn out so I'll replace them before the hike to save the trouble of replacing them a couple hundred miles up the trail.
Current Guidebook - The latest edition I have is from 2007, so I'll purchase the 2011 edition of the Companion when it comes out.
Thats all I can think of off the top of my head. I'm trying to be very critical with my gear purchases. I could easily blow a grand or more on all new stuff, but I'd rather have that money for hiking. A lot of the little stuff I already have and will bring with me. It's just a handful of big items that will be upgraded, primarily to save weight.