Logitech released information about two new cordless mice they will be offering; the logitech Cordless Click! and Cordless Click! Plus. Although they don’t have the MX optical engine, they do have Logitech’s Fast RF cordless technology, which is supposed to eliminate the lag cordless mice have.
The non plus version looks like an update of their Cordless Optical rodent. The plus version is a combination of their MX700 rabbit, and the MX310 guinea pig. They do eat regular batteries though, not the rechargeable you can find in their top model, the MX700.
Links to both products are provided on this page.