Congratulations! Welcome to the 21st century! Please be aware that your meal replacement pills will be arriving at your matter replicator terminal shortly!
Seriously though, the D70 was my first DSLR, and has a very special place in my heart. We still have three in constant use at Gulliver, and they've held up very well over the years.
I think you'd still get pretty good landscape results from it if you use the right lenses and settings.
Good plan on the D3 and D300 down the line, but keep an eye out for the much rumored "D3x" with 17+MP