"I am still carrying my solar system (panel, charger, batteries), and electronics suite (GPS, PDA, camera) so I suppose those really aren't necessary."

Depends on what you do with them; if you find them worth carrying, you're the only one you have to answer to ...

If you (a) still want 'em, and (b) are willing to spend some time and money, one potential weight saving is to combine them in the form of a smartphone. I carried one on the PCT this year and it gave me all three functions you listed plus more.
It's not a trivial transition, however. Look here if you're interested in some specifics:
http://postholer.com/smartPhone.html