Lithium Ion batteries are so much better than NiMH. No more memory effect, higher capacity given the same available space, much less affected by low temperatures, great charge retention (they don't need to be recharged, like NIMHs, if you leave them lying around for a month or longer). So you can always have a fully charged spare handy without having to top up the charge regularly. Changing the battery is also much faster with a single LI-Ion pack than juggling four NIMH cells. There's only one drawback: the price. Being able to use standard lithium cells is a handy plan B feature. You can keep them lying around as 'insurance' for up to five years, then pop them in and shoot.
If you mean "batterypack" as in the extra grip (like the MB-16 for the F80 or MB-100 for the D100), then no none of the literature so far has made any mention of it at all and as Nikon is pretty up front with what accessories will work and what will not, it seems that no grip will ever make it to market (unless the D70 has the unused electrical contacts on the base of the camera).