It doesn't look like it's meant as a C860 replacement, other than in the sense of replacing the current top model.
For one thing, the C3k doesn't include Java (though it may be possible to install cvm or evm, I don't know); a Japanese article mentioning this said that Java users were (apparently) expected to stick with the c860 if they needed it.
Some stores here still carry the older/lower-end models, such as the A300 and the C700; other stores, though, have the c750 as the low-end model.
Time will tell, I guess.
- ashikase
anpachi, gifu, japan